Depending on the merchant website this can be one or multiple coupon codes. The coupons initially do not display the savings or offers. You need to hover the mouse cursor over an icon to see those in a small popup next to the mouse cursor.

A click on a coupon code – after selecting the one offering the best deal – copies it to the clipboard so that it can be pasted into the order form on the target website easily. This is done either by right-clicking the coupon field and selecting paste or by activating the coupon field first and the keyboard shortcut ctrl-v to paste it into.

The Firefox extension Coupons Helper will display coupons as soon as you visit a merchant website by default. It can however be configured to only reveal coupons on a shopping site’s basket page.

This has both advantages and disadvantages. The core advantage is that you are not distracted by coupon code notifications on a site. This may also prevent you from making impulse buys just because of the coupon. It on the other hand means that you may need to alter the items in your shopping card depending on the coupons on offer to meet the requirements. If you know the requirements before starting to shop on the site you may be able to select the right items right away to speed up the process.

Coupons are currently only supported for shopping sites in the United States and France. Users who shop in those countries regularly can benefit a lot from the CouponsHelper extension. It supports a wide variety of sites, including sites such as Perfumes, Dell, Walmart or FedEx.

You can use the coupon finder directly on the developer site as well in case that you do not want to install the Firefox add-on or use a different web browser.

Update: There is also a Chrome extension available.

Context Peek is a Firefox add-on that streamlines the process by displaying the information in a small popup next to the select word or phrase on the page.

The add-on is very versatile, as it allows you to configure your own services in addition to the default services it ships with. The three look-up services it ships with are Wikipedia, the Free Dictionary and Google Translate.

Lets take a look at how it works first before taking a look at the configuration of new services.

All you need to do to use the add-on is to select a word, phrase or sentence first. You then right-click the selection and select Context Peek > Service from the context menu.

The add-on opens the information provided by the selected service in a popup which auto-closes when you click outside the popup window.

To configure existing services and add new ones, you select Context Peek > Configure from the menu.

Configuration is a little bit tricky as you need to have a target url at hand to add new services. You can basically add any server that uses parameters in the url. Lets take Amazon for an example. To begin with you need to perform a search on Amazon. I suggest you search for TEST which makes identification in the url easier.

You then take the target url

http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=TEST&x=6&y=15

and replace TEST with the variable used by Context Peek which is CPTEXT so that your target url for Amazon would look like the following:

http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=CPTEXT&x=6&y=15

All that is left now is to enter a title that appears in the context menu to add the new option to the available services.

Context Peek’s configuration can be a bit tricky. It could however be well worth the troubles as it provides an elegant way of looking up information on the Internet without having to open a secondary tab or browser window to do so.

Firefox users can install the add-on from the official Mozilla add-on repository. The add-on itself requires no browser restart. Changes to the configuration on the other hand do.

Enter Replace Bookmark for Firefox. The core purpose of the add-on is to replace an existing bookmark of the same root domain with a new one. You do not have to use the add-on, but whenever you want to replace a bookmark you should as it overwrites the old bookmark with the new bookmark information.

This technique is obviously not helpful if you are bookmarking single page contents, but imagine reading an ebook or comic where each new chapter or page is displayed on its own page. It may be difficulty to remember if you have stopped reading on page 48, or 51 the last time.

Replace Bookmark is a restartless add-on for Firefox which means that it can be installed, disabled and removed without restarting the browser.

It leaves the standard keyboard shortcut for bookmarking a page untouched (Ctrl-d) but adds its own shortcut to replace one of the existing bookmarks (Ctrl-Alt-d).

Just press Ctrl-Alt-d when you are on a page and the add-on will displays a small window with all existing bookmarks of that domain.

Now it is up to you to select the bookmark from the list that you want to replace. A click on ok replaces the selected bookmark with the bookmark of the active page, and cancel cancels the operation.

Replace Bookmark is handy for users who use bookmarks to save their read progress. Firefox users can download the add-on from the official Firefox add-on repository.

Or your form data was submitted but you cannot remember what you have entered in a specific field, and when you go back the web form is empty again.

Firefox does not have options to direct the submission of a form to a new tab or window. This usually means that you cannot go back to access the data that you have entered into the form. It may even be worse if you have started filling out a multi-page form.

The Firefox add-on TabSubmit adds options to Firefox to direct form submissions to a new tab or window. This leaves the page with the form and data you have entered on its own page; Excellent if you need to go back to that form to see what you have entered or if you need to re-submit the form.

TabSubmit is a complete re-write of the now defunct SubmitToTab. The developer on top of the existing features added support for the HTML5 formtaget attribute, switched from re-writing existing handlers to using event listeners “to hook into the mouse behavior” for a safer and more robust approach and added support for SeaMonkey.

The add-on is restartless which means that it can be installed and uninstalled without browser restart.

The Firefox extension does not change the default way of submitting tabs. You can still left-click on any submit button to submit the form to the same tab.

If you middle-click on the submit button, or hold down Ctrl while left-clicking, you will submit the form to a new tab instead. Holding down Shift while left-clicking submits the form to a new browser window instead.

The new form submission options take some getting used to time but it is the only practical option to implement the feature. You’d otherwise open web searches and other basic form submissions on a new tab or window automatically which would result in chaos.

TabSubmit is an excellent Firefox add-on for users who regularly use sign-up forms and submission forms. The add-on works with all versions of Firefox from 3 onwards. The restartless feature is only available under Firefox 4. (via)