Tomorrow the iPhone 3G comes roaring into stores, but we got a lucky break today when the 2.0 firmware was discovered online. The app store is also live in iTunes, so I took it upon myself to download a few apps (mostly free ones) to get a feel for them. Here are my first five:

(FREE) The one thing I’ve desperately wanted out of my iPhone was a chat client that worked on a non-jailbroken phone. I couldn’t find an app that would work like Adium or Trillian, which would cover all your bases in terms of chat. If you’ve come across one, let me know! However, the AIM app works really well so far, even if it’s missing some of the iChat sleekness. UPDATE: However, as Dave Zatz points out you cannot run apps in the background, which makes running an IM client a little more annoying.

(FREE) In lieu of purchasing an Amazon Kindle like I’ve been considering, I took the advice of many to wait for an eReader for the iPhone. Here’s the first incarnation of one that I’ve come across. You can download hundreds of books from sources like eReader.com and FictionWise.com, although I’d still rather have a larger screen for reading if it were for an extended period. My eyes are strained enough as it is! The page flipping is very cool, and I feel like I’m going to get a lot of use out of it.

(FREE) Math? Not so much my specialty, especially when it’s a large group and there’s check-splitting involved. There are serveral web-based apps for iPhone, but this one will come in handy at my favorite restaurant in town that for some reason never has cell reception. The interface is just about as simple as you can get, which will help expedite the paying process.

(FREE) Midomi is a wonderful little app for figuring out that song that’s been stuck in your head for days. Either sing a clip, or type in the few words you remember, and the app will bring up some matches. You can then purchase the tunes or watch them on YouTube. Folks on my FriendFeed are saying that Shazam’s app works faster and more reliably, but I haven’t given it a shot yet myself.

($2.99) The one app that I’ve actually spent money on is MobileFlickr. I’ve made good use of the dedicated Flickr email for sending in photos from my phone, but this has a lot more obvious functionality built in. You can so just about everything on the mobile version that you can accomplish on the web, short of editing and organizing.

It seems that most of the big names have apps ready to go, like eBay, Twitterific and MySpace. There’s a good number of free ones to choose from already, and while I’d be hard-pressed to spend $9.99 on an iPhone application, the Lonely Planet Japanese Phrasebook does seem pretty tempting!