AIM – Instant messaging has never been one of the iPhone’s strengths. Apple’s limitations on allowing apps to run in the background means that you can’t receive an IM notification while you are working within another program. Close it down, and you are off-line. A new version of AIM seeks to change this and give you a bit more multitasking flexibility.

It works by sending you a text message that you have a new IM – even when you do not actively have the AIM app open. AIM keeps you logged on for up to 24 hours after you close out of the app. So if one of your AIM buddies wants to start a chat session, you will get a text notification that they are messaging you. Then you can fire up AIM and start the conversation. AIM will also text you when the system logs you off. So making sure you have a flexible SMS plan is probably a good idea.

AIM takes interacting with mobile devices one step further by giving you the ability to send a text message to another phone. That person can then reply by SMS and you will receive it within AIM as an IM. If you are not using the app you will get a text message notifying you of the reply.

Setup was pretty easy, especially if you already are an AIM user. All your current buddies are on the list and available for chatting with. There is a series of screen to taps through that shows who you have on your list, and who is offline or available.

The attempt to give you some flexibility in instant messaging is admirable and another way to stay in contact with others through your iPhone. The app suffered a few hiccups during testing. For example, I did not always get a text when I was still “signed in” and IM’d by a friend. Managing the system of text messages is also a bit cumbersome. Should you choose to get a message every time you receive an IM, expect for the messages to pile up.

AIM is a good addition to your iPhone if you are a frequent AIM user and want more access to your buddy list. If you are more of a casual IMer, the free version will probably work just fine without the extra features available in the newest version.