We work on a lot of stuff that involves graphics, interfaces, and actual design work here at CollegeKidApp which makes for a great time because everyone on our team gets to pretend for a few minutes that we are part artist. We don't feel like we're horrible at art or design but we're definitely not experts by any stretch of the imagination. Design becomes an even more difficult task when you're working remotely from your home and you can't take a look at something in Photoshop and talk about it in person. To help out, we use an application called Skitch.
I've had this application for a while but we've never really started utilizing it for CollegeKidApp until recently. Skitch allows a user to take a screen shot and then make notes or drawings on the screen shot with ease. You can also save the shot in a variety of different formats (great for saving to the desktop and inserting into a blogpost or attaching to an e-mail) or even publish to a secret website which you need to be given the link to gain access (as example here). It's wonderful at putting together quick mocked up image to help get the point across when talking about design over IM. It's saved us tons of time when working to do artwork when working independantly and we hope it helps you as well. It's Mac only, so sorry if you're running a PC. If anyone knows similar software that is Windows compatible, send me an e-mail and I'll be sure to post a link to it as well.