eBay has launched a service to alert buyers via SMS of events in auctions they are participating in. Text messaging is just one of three new alerts eBay launched, but is the only one available today. Alerts via phone call and IM will launch next month.
Once signed up for text alerts for a given auction, messages are sent when you are out bid or the auction is ending soon. In the case that you're outbid, you can re-bid by replying to the message. The SMS alerts feature costs $.25 per auction for up to 10 alert messages. The fees appear on your wireless bill.
eBay also runs a free WAP site at wap.ebay.com that lets users search and bid on items.