I'm hanging out at Web 2.0 for next couple days. I'm currently in a session about Web Services with a bunch of interesting people. This session is really what everyone is here for - using the web as a platform. The session has just started so I don't have much to say about it yet (maybe I'll update this post afterwards). Hopefully it quickly goes past they "why is web services important" part of the presentation and gets into the meat quickly. (eBay's web service gets over 1 billion queries a month. Pretty cool.)
One of the interesting people here is from Bonfire Media who have launched a J2ME app called Pocket Auction, which uses the eBay API and presents your auctions, etc. on the go. Very interesting. I think there's lots of opportunity for these types of apps using J2ME. It's too bad that XML processing and Web Services aren't cooked into J2ME like they should be. There's lots of apps I can think of that use the current popular web services: eBay, PayPal, Amazon, etc.
XML data sent over cellular connections are a bit heavy, though... I wonder if they have some sort of proxy in between? It'd be interesting to know. I may raise my hand when it comes around to that subject.