Sizer is a great freeware application that lets you resize any window to a predefined size. It is only 30k unpacked and can be started from any location on your computer. Once started a icon appears in the system tray that allows you to configure sizer. You are free to add exact pixel sizes to the configuration which appear when you right click any window that is open. You may also opt to reposition the window while resizing it, sizer offers some default locations like top left or bottom right but has another option that makes it possible to enter the coordinates yourself.
Why would someone need this tool ? First it is useful for webdesign purposes, if you want to test your newly created website in a certain resolution you could change that resolution for your monitor or you could use sizer to resize the window to that resolution keeping the monitor resolution. A second idea that makes sense is that you could use sizer for screenshot purposes.
Lets say you want to have all windows that you make screenshots of in the exact same size and position. Sizer can do that.
Related posts:
Resize The Firefox Window With GeometryAutomatically Move And Resize Windows
Resize Windows
Freesnap: Resize Windows with the keyboard
Save Unlimited Websites as Images
Resize Popups in Firefox
Window Management Software Taekwindow
Windows Vista Taskbar Resize
Size-O-Matic is another one that does the same thing and packed in on exe. http://www.pythoness.com/