One of the biggest complaints from iPhone owners is that there is no instant messenger built-in. Thankfully a few web-based solutions are available and have come to the rescue. As of today, one of the most popular online chat clients, Meebo, is now available in a new and improved version on the iPhone that’s easier to use than the previous version that they hurried to get out when the iPhone launched.

Webware wrote up a nice review of the new Meebo chat app and says that it’s very intuitive, and your buddy list is now “finger friendly, and easy on the eyes.” They also mentioned that your buddy list makes use of the entire screen, and all that needs to be done to begin chatting with someone is to click on their name. The image below  on the left shows what a buddy list would look like on the iPhone, and the image on the right shows what a chat conversation would look like:

Meebo buddy list Meebo chat window

Judging from the comments on the Meebo Blog, users are pretty happy with the results, and others are hoping that the team will optimize Meebo for Windows Mobile 6 users. If they’ve taken the time to optimize the service for the iPhone, I’d think they’d be able to easily optimize it for other mobile phone users as well.

While Meebo is one of the most popular online chat clients, there are others as well who also have iPhone support. One of them is called eBuddy which anybody can use (just go to on your iPhone), and another option is Trillian. The only downside with Trillian is that you’ll need to be an alpha tester to try it out. They say that it could be the most “alpha” quality product delivered, meaning it could potentially have lots of bugs. Once they get all of the bugs ironed out and move it away from the alpha stage, I’m sure Trillian Astra for iPhone will be another great chat solution.

So I guess the problem that the iPhone shipped without a built-in instant messenger has been solved by some of the most popular online chat clients. They’ve got an awesome opportunity right now to recruit new users, all thanks to Apple and the iPhone. For those of you who have an iPhone, give Meebo a try and let us know what you think!