Many of our Google Summer of Code applicants have mentioned that they'd like to work on desktop or mobile clients. Since the application phase begins today, I thought I'd post an entry for people to mention what features and functions they consider essential in a desktop or mobile client. This will let our GSOC applicants see the thoughts of people who use the site regularly, so they can work those thoughts into their specs as they build their application.

So, this is a post for people to comment with:

* What features/functions do you consider essential in a desktop/mobile client?
* What features or things would you not want a desktop/mobile client to do?
* What are things you've loved and hated in clients you've used previously?

It's okay to answer separately for both desktop and mobile clients, since the two are only very loosely related. The more feedback you can give, the more it will help our GSOC student applicants as they design their application.