The built-in web browser in my cell phone sucks badly, as do most of them. Why doesn’t someone put an RSS reader in a cell phone?
I publish a WAP version of MobileTracker (wap.mobiletracker.net). It's better than an RSS feed because it works on 95% of cellphones without any special software, and it takes a lot less cruft. No meta data to cost readers more time/money.
But for something like the sidekick, RSS would be great.
I use a Radio feature designed quite a while ago to email headlines to my hiptop every hour. It's quite useful, though it'd be better if the URLs could be included inline (the hiptop mail client pulls all the URL out and drops them at the end of the message). There is an under-development hiptop RSS reader, but I don't know how far it's gotten so far beyond the screenshots.