We all know those three title bar buttons well, but there are a myriad of other things you could want to do with a window. Instead of applying keyboard shortcuts or hiding them in context menus, Chameleon Window Manager puts them in a familiar location: the upper right hand corner of your windows. You can customise which buttons you want to appear, each of which performs a different function: you can snap that window to the left, snap it to the right, change its transparency, make that window sit on top of all others, hide everything except the title bar, and minimise it to the system tray. It's surprisingly snappy, too, so it doesn't feel like you're running some hacked buttons over your windows — it just adds the ones you wish you always had.
Chameleon Window Manager is a free download for Windows XP and above.