It's been a while since I've played any community tournaments...maybe I'll be able to get back into it this year. Anyway, I remember the few that I participated in, I'd always use the Ctrl+PrntScrn and paste into MSPaint, then crop the edges, then save, then upload to some host site like tinypic.
I downloaded a neat program that I use for work and would be perfect for this:
http://download.cnet.com/Jing/3000-13633_4-10744274.html
It's called JING, and it leaves a little yellow orb at the top of your screen. when you want to capture something on the screen, you mouse over the orb, then it gives you options where you can select the part of the screen you want to copy. After you copy you can even insert text-boxes, arrows, highlight boxes, etc. And then you can save it to your desktop. Still have to upload it to another site (I think so anyway...it might actually auto-upload and give you the sharing link right there). But like I said, it's something I use for work instead of the print-screen option then screwing around in MSPaint.
Have fun.
Pillsy