Magic Set Editor.
 

http://magicseteditor.sourceforge.net/

There's the software. Let's see what we all can come up with. ;)

http://i43.tinypic.com/1111q9k.jpg

Edit: Better?

my magic nerdery must tell you that the above card is oh so wrong in oh so many ways.

Ill contain the rage to GREEN DOES NOT DEAL NONCOMBAT DAMAGE

also, Ive used MSE to create a block once. it was awful when looked at together, but the individual cards were ok.

If you're talking about the inverted side, that's colorless. You may weep now. ;)

you use green mana to cast it, and green to flip it. thats a green card, the same way Ghostfire is a red one.

I know green doesn't do direct damage. That's red's job. Or it used to be when I still played. Keep in mind this was thrown together out of boredom sometime last year just to play with the system.

Oh, and POST MOAR CARDS!

http://i41.tinypic.com/11c3yg6.jpg

Based on my stuff from the Gleemax RP on the wizard of the coast forums:

http://i278.photobucket.com/albums/k...2136/cards.png

You can save in PNG!? I didn't know you could save in other formats!

http://i43.tinypic.com/244e5n9.png

Gotta love this.

I made some of these a while ago:
http://img224.imageshack.us/img224/2...inatreenj7.jpg http://img224.imageshack.us/img224/8...antmentrb9.jpg http://img224.imageshack.us/img224/5576/stophalfyj6.jpg

http://img26.imageshack.us/img26/7596/thegoggles.jpg

Maybe if I actually knew Magic I could come up with something decent, but hey, the thing can do Yu-Gi-Oh Cards as well!
Sorry, I know, TMI.