Every time I find a laptop bag I say I love, Eric rolls his eyes. “You say that now, but in 6 months you’ll be complaining about it like all the rest.” I tell him that the problem isn’t me, it’s that the perfect bag hasn’t been invented (that I can afford, at least) so until then I settle for the best I can get with one hand while I’m looking for utopia with the other.

That’s the way I am with Twitter clients right now. I tried at least 6 of them on the iPhone, (Tweetie and Twitterific are currently my favorites) and I’ve tried so many on the Mac desktop and in the browser window I’ve lost count. On the desktop, none quite fit the bill for this tweet addict who has posted over 5,500 updates in 2.5 years.

In no particular order, here’s what would make a perfect desktop Twitter client for me. Tweetie is pretty close, but I’m getting impatient at the lack of feature-improvement updates. I understand that @atebits is a one-man show and he’s moving. Doesn’t make waiting any easier.

Desktop application. I live in a browser for everything else. But for some reason I prefer my tweets in a separate application. Oh, and on the Mac only. I don’t run my Windows XP virtual machine often enough anymore to consider a Windows client.

Multi-account support. I also do some tweeting for C3.

Growl notifications or something similar. The AIR clients I’ve tried (Seesmic Desktop, TweetDeck, Twhirl) can’t use Growl, so they have their own little box that pops up in the corner when tweets come in. That’s fine, as long as I can set it to only notify me when I get @ replies or DMs (direct messages). I don’t want to be notified on every tweet, just those that need my attention. Check one against Tweetdeck here.

Play nice with others in its own space. The AIR clients take a ridiculous amount of CPU and RAM after running for just a few hours. It’s not the developer’s fault. It’s Adobe.

Let me decide how it looks. Seesmic Desktop has some nice features, but on every release I keep waiting for the real interface. It feels clunky, especially when I resize the window and columns are cut off. The type is huge in Tweetdeck, and I don’t like white type on the dark background. I want to be able to pick a theme and the fonts like I can in Twhirl. Or at least let it be pretty like Tweetie or Twitterific.

Tell me about my API use. I like the way Tweetdeck tells me how many API calls I’ve used and how long until the next update. It also lets me adjust how the calls are issued. I want to know about @ mentions and DMs as soon as I can, then the tweets of folks I’m following, and finally update the searches. Tweetie and Twhirl will only tell me when I’m in the penalty box, and Twhirl only counts its own calls.

URL shortening and picture (twitpic) upload support. Seems ridiculous nowadays to have a desktop client without them. Yes, I’m talking to you Twitterific.

Single column, with views I can select as I need them. I can’t stand the multi-column view of Tweetdeck and Seesmic Desktop. I’ve tried, but it’s just too much at once and takes too much screen real estate. I want a single column containing the latest tweets from the folks I’m following, with a sidebar that allows me to see @ mentions, direct messages and saved searches as I request them (yet still notify me as needed). Tweetie is on the right track here. But I want to be able to save searches between sessions. Similar to the Twitter home page. I know I can close columns in Tweetdeck, but it’s too much hassle to get them back, even with its new ability to save searches on their server. Twhirl is closest to what I want here, as is Seesmic Desktop if it wasn’t so clunky.

Conversation view. I like being able to click on a tweet that’s a reply and see the history of what the person is replying to. Tweetie wins here. Tweetdeck comes second.

Profile view. If I click on a user, I want to see their last tweets, whether they’re following me (so I can tell if I can send them a direct message) and I want to have an easy way to get to their site, see their bio, etc. Many of the clients will let me follow/unfollow/block, but it drives me nuts to see a client prompt “Follow user” for someone I’m already following.

Trending topics and searches. There are a number of keywords and brands I track, but I don’t need to see them all the time. The iPhone version of Tweetie lets me save searches to pull up when I want them. The desktop version has a great search interface and I can see searches in a separate window when I want, but if I quit Tweetie those searches are gone.

The ability to filter tweets based on hashtag. Yes, I’m talking to you #spymaster.

Not too much to ask, is it? 😉