![In Tweetie for Mac’s preference panel, there is a checkbox:
[ ] Show ads
when you try to un-check that box, the above dialog box appears.
I’m reinstalling stuff on my iMac, which means re-entering all of my registration codes, etc, and I obviously haven’t done Tweetie yet, but it strikes me as a very nice, not-too-in-your-face way of letting your users know that there’s a “register” option available.](http://26.media.tumblr.com/tumblr_kyxvo1QABr1qz8t7bo1_500.jpg)
http://www.atebits.com/tweetie-mac/
In Tweetie for Mac’s preference panel, there is a checkbox:
[ ] Show ads
when you try to un-check that box, the above dialog box appears.
I’m reinstalling stuff on my iMac, which means re-entering all of my registration codes, etc, and I obviously haven’t done Tweetie yet, but it strikes me as a very nice, not-too-in-your-face way of letting your users know that there’s a “register” option available.

http://twitter.com/tj/status/5611794035
See larger version of this image.
The funny thing about that post? I sent it at lunchtime yesterday from Tweetie on my iPhone.
But look at the time it posted.
It’s currently 11am on Wednesday, which means Twitter got the message around 1am.
Around 1am last night I opened Tweetie to read Twitter while waiting for the sleep to kick in.
I must have exited Tweetie at lunch before it had a chance to “seal the deal” but then when I restarted it, it picked up where it left off.
Weird, eh?