With the recent news from Apple that iPhone OS 4.0 will be released this summer, I am giving very serious consideration to getting one. I have a 2+ year-old Motorola RAZR 2 from T-Mobile and it no longer is practical for what I want to do with my cell phone. I was hoping to get the Nexus One, but Google has made it difficult for existing T-Mobile customers to obtain one (I have a family plan). My wife bought an iPhone around Christmas and loves it. Now that Twitter has announced the purchase of iPhone app Tweetie, I'm more than ready to get an iPhone. My wife has experienced no problems with AT&T's coverage (we live in the Chicago area) so network performance is not a concern.
Twitter apps for iPhone