Consider all these cursory overviews at best, as I've just spent a few minutes with each. All testing was done over Wi-Fi, not EDGE or 3G. Most of these first applications are the ones I'm recommending. I'll be adding listings for applications I've been less impressed by later.
Each 'Price' hyperlink connects directly to the App Store page for each application.
Twitteriffic
Price:
Free
Should I?:
Yes
The latest build of Twitteriffic from Icon Factory adds location-aware tweeting, picture uploading, and a variety of interface options including a left-handed mode. It's giving me errors that imply my login is incorrect but is still pushing and pulling tweets. As with all things Twitter, this may be a problem with the service, not the software accessing it.
Like the free desktop version of Twitteriffic, the iPhone version has in-line ads that are nominally intrusive. If you'd like to ditch them entirely, a premium version is $10.
All-in-all a very polished application that will give Twinkle a run for its money.
Remote
Price:
Free
Should I?:
Yes
With a single download, Apple's official Remote software for the iPhone and iPod touch pretty much negates the need for something like the Sonos music system for most households. Remote adds an interface for controlling your computer's iTunes or an AppleTV that is nearly identical to the iPod interface on the iPhone, minus a few niceties like Cover Flow.
Album art is slurped up over the air; frames from movies being played are occasionally sent to the phone to show you what part is being watched. It's top-quality integration of various platforms.
It only works over Wi-Fi, so no turning on music at home while you're at work to confuse the dog.
Remote is going to go over great at parties. Now someone just needs to find a way to use the iPhone to dim the lights. (Expect Apple Ambiance products late 2011!)
AIM
Price:
Free
Should I?:
Maybe
The official AOL Instant Messenger client is a solid first entry, capable of easily bringing down lots of contacts and holding instant message conversations. It does not appear to work in the background even using the Apple messaging server that was revealed weeks ago. That's a huge disappointment, but one I expect will be remedied soon, either by AOL or a third party.
It's free, though, so no harm in slapping it up there. It is better than nothing.
Jott
Price:
Free
Should I?:
Wait
Jott is an interface to the free Jott.com voice-to-text service. Tap to record a short message and soon you'll have a text message inserted back into the Jott iPhone app's to-do list.
Unfortunately, it doesn't look like the Jott app is quite ready for production. On my first attempt the message didn't come back within a couple of minutes. (This may be typical for Jott; I've never used the service before.)
Worse, when I tried to open the app later to check if my message had been delivered, the app crashed. They'll get it worked out soon, I'm sure.
Loopt
Price: Free
Should I?:
Yes
A location-aware mobile service that ties into Facebook, Twitter, and other platfors, Loopt will show you not only where your other Loopt-using friends are at, but highly rated nearby restaurants. It has an easy mechanism for inviting friends to Loopt as well as determining which of your contacts are already using the service. So far I have zero friends that have accepted my invites — hrm! — but the potential for connecting with other people in the real world is going to be incredible.
One irritation: Loopt (and other applications that use location data) prompts for permission each time it accesses the GPS (or GPS-a-like services of the iPhone EDGE). I would like to grant the app a permanent proxy to that service, but it's not a huge deal.
Loopt could be a massive hit but like all social services it needs more users to become ubiquitously useful.
Super Monkey Ball
Price::
$10
Should I?:
Yes
While many of the games available for iPhone 2.0 are sort of embarrassingly unpolished, Super Monkey Ball is bright, pretty, and immediately accessible. That's not to say that it's easy — I threw my poor monkey off several platforms before getting the knack, but my very cursory play (about 10 minutes) give me an inkling that I'll be rolling my monkey around with less-deadly precision in no time.
One quirk: I couldn't figure out how to get out of the play field back to the main menu without quitting the app entirely.
If nothing else, this is a good app to show off the phone to your friends. However, there doesn't appear to be a free demo, which is a shame.
Exposure
Price::
Free
Should I?:
Yes
Fraser Spiers' Exposure is a mobile gateway to Flickr, with full access to your contacts' photos, nearby images based on geotagging, and complete search of the Flickr library from your phone. It's the best mobile interface to Flickr I've ever seen. And it's free, although ad-supported. A $10 version called "Exposure Premium" comes without ads, but frankly I didn't find the ads in the free version to be distracting at all.
Essential for Flickr users.
Midomi
Price::
Free
Should I?:
Yes
Midomi lets you hum a song into the iPhone (10 seconds or more is best), then tries to match that snippet with a real song. I just hummed the only song that is ever on my mind — Kelly Clarkson's masterpiece "Since U Been Gone" — and was presented with a selection of options for the correctly identified song in seconds, including links to buy it on iTunes or options to watch it on the iPhone's built-in YouTube viewer.
What would be an amusing trick in a web browser is an impressive and handy application on a mobile phone. It's totally free — and a total hoot. Get this one immediately. (I expect it won't be quite as instant over EDGE, but on 3G it should be fine. Also, the first time I tried Midomi the app stalled out on me, but it appears to be working fine now.)
More coming, but I wanted to get these going. Please chime in with your discoveries!