AviF's Profile

There are things for mac that already do what you're asking. There's an app called AppFresh which looks through your applications and uses appcasts (it looks to iusethis's appcasts if it can't find the developer's) to automatically install updates to your software. There's a widget called App Update that looks through your applications and gives you links to the update. It uses Apple, MacUpdate, and Version Tracker. Both look at 3rd party apps as well as apple apps. Enjoy!