Jon Udell has a post about the two techniques used to reduce bandwidth when downloading feeds. Those examples were pretty cool. I knew there was a header that could be used to check if a site had changed, but I never looked it up before. This is something I should add into the OPE download tool, presently called PalmTorrent. It would be really cool to have your apps setup so that you could update them online, the way that SoftwareUpdate allows for, but running through the whole catalog to see what has been updated.