Because I’m in a year-end list-making mood, and I’ve got insomnia, here’s a handy list of my favorite iPhone apps. All links go to the App Store page on iTunes, so don’t be alarmed.

iPhone client for
This is the best twitter client for any platform, as far as I’m concerned. I bought a copy of Twitterriffic and don’t regret it, and I’m still using the desktop version on my other machines. But this is one case where the “less is more” philosophy doesn’t quite hold up. Tweetie lets you separate messages into replies and direct messages, search for keywords and on more general “trends,” and most useful: examine profile details. Seeing who’s following you (and who’s following them, and so on) is the best way to build up a network of people you don’t know.

Speaking of people you don’t know: I never saw the appeal of twitter initially, but now I’ve become one of those annoying types who says it’s “indispensable.” My favorite of the people I don’t know that I’m following is Joshua Green Allen, or @fireland, who’s so funny it kind of pisses me off.

Free e-book reader
I don’t understand this one at all; it came out almost as soon as the app store opened, it’s completely full-featured and works perfectly, and it’s still free. You can download books from within the app, directly to the phone, or you can add your own. I haven’t tried reading a full-length novel on it yet, but at least for reading short fiction, it’s perfect.

Free RSS feed reader
This is especially useful if you use NetNewsWire as your desktop RSS feed reader (as you should, if you use a Mac), since it keeps your read/unread count in sync with the desktop version. The author updates the app frequently, and he’s always looking for ways to make it faster, simpler, and easier to use.

Air Sharing
File transfer and viewing utility
This lets you copy files directly to the iPhone, without going through iTunes or a desktop client app. It contains viewers for most common file types like video, audio, and iWork/MS Office documents.

City-building game
This is a surprisingly full-featured port of SimCity; it doesn’t feel like they had to sacrifice much to get it to work on a phone. It’s roughly “SimCity 2800,” since it’s got the art assets and most of the concepts of SimCity 3000, but not quite the entire game (no subways, for instance). Seeing as how SimCity 3K is the only game that I’ve spent literally an entire day playing, this could be dangerous — luckily, the game drains the iPhone’s battery pretty quickly, and doesn’t scale that well to huge cities.

Now Playing
Free browser for movie showtimes and reviews

Free Japanese/English dictionary
Works best if you enable the Japanese keyboard(s) via Settings->General->International->Keyboards.

Free & Paid versions, saves web pages for offline reading
Simple and easy to use, works perfectly even in the free version. Great for plane flights.

Task management software
This one is overpriced and a little over-complicated, but it’s the best one available for the phone right now. The UI just plain works like it’s supposed to, and it turns out to be the fastest and easiest at entering new tasks (which is what you do most often) and sorting them into different contexts. It’s very hard to justify paying $20 for a to-do list app (and much, much more than that if you want to sync your list with the desktop!) but if it’s something you use a lot, it’s the best you can buy.