Windows software update

You may be familiar with the process Windows uses to update itself but what about all the other software? Is everything else up to date? "By using up-to-date software you'll reduce the risk of encountering bugs and will benefit from more features." (betanews)

Three freeware programs that help you stay on track:

1. Sumo - my favorite
2. File Hippo Checker - still fairly new, but promising
   
3. AppUpdater - an open source (GPL) checker
   

I thought the non-free Mac application "AppFresh" had no Windows equivalent but there are several. For more info, I did a write up for this over at portablefreeware's forums.

Update: there are apparently a LOT of free software version checkers (scroll down on this page).