You won't find iChat or any instant messaging on the iPhone. For whatever reason, Apple decided against instant messaging. There is a workaround, though - Meebo.
If you Want to get true instant messaging on your iPhone while you’re away from your computer, There are several Web based Instant Messaging clients for the iPhone.
1. Mobile AIM
AOL’s Mobile AIM Service (mobile.aim.com), can automatically forward basic iChat and AIM messages to your iPhone as SMS messages. When you reply
to 1 of these messages, your reply is also sent via SMS. AOL’s system then converts it to a standard AIM message or iChat and forwards it to the recipient.
2. JiveTalk
One of the most promising Beejive’s JiveTalk. Using JiveTalk is sim fire up Safari on your iPhone and head to iphone.beejive.com. While it may no have all the niceties of iChat or Adium, JiveTalk does let you send and receiveinstant messages with multiple buddies And it supports multiple accounts on A Google Talk, ICQ, Jabber, MSN, and Yahoo Mail. What’s more, it even feels like a software, with chat bubbles and dialog box that fade out.
3. Meebo
1. Mobile AIM
AOL’s Mobile AIM Service (mobile.aim.com), can automatically forward basic iChat and AIM messages to your iPhone as SMS messages. When you reply
to 1 of these messages, your reply is also sent via SMS. AOL’s system then converts it to a standard AIM message or iChat and forwards it to the recipient.
2. JiveTalk
One of the most promising Beejive’s JiveTalk. Using JiveTalk is sim fire up Safari on your iPhone and head to iphone.beejive.com. While it may no have all the niceties of iChat or Adium, JiveTalk does let you send and receiveinstant messages with multiple buddies And it supports multiple accounts on A Google Talk, ICQ, Jabber, MSN, and Yahoo Mail. What’s more, it even feels like a software, with chat bubbles and dialog box that fade out.
3. Meebo
Meebo is a Web service that lets you use IM via meebo.com. Meebo supports Google Talk, MSN, Yahoo, and AIM. For Mac users, AIM is compatible with iChat. Meebo is free to use, and you have to sign up for an account.
Why would you want to use IM through a Web site? You could use Meebo if you're at a public Internet kiosk that has no chat client installed. Or you can use Meebo on an iPhone via the Safari browser.
It's pretty obvious that they didn't want instant messaging as they have always stuck to the theory "no background services" as they burn up cycles and thus battery. IM would require a "always on connection"...not worth the trade off.
Look for a solution in the coming version 3.0. I'll wait until their battery saving solution is live. In the mean time check out the 3.0 preview video on apple.com for details.