I love this site so far, thank you sebi for the great idea. I was looking for something like this, without the terribly clunky interfaces out there or the bogged down advertising. "AJAX" style pages are so much nicer.

Some things I'd love to see, or would offer to help program are:

Search for the text of cards when adding instead of just the name... I have a hard time trying to remember the name of all the cards, but I can remember what they do. :D This would be easy enough to do since the card text already pops up when searching for card names, although it's only a teaser. A little check box of which you would like to search for would work out nicely, I think.

Now that I think about it I'd also like to be able to search by other means. My favorite deckbuilder right now is onlineplaytable.com. While the download is out of date (I had to manually add Alara Reborn and M10), the card searching interface is simple and precise. Being able to filter for cards by Color or Type would be great. Sometimes I just want to troll through all the cards of a certain color grouping by their subtype.

I'd love for the ability to comment on your friend's decks, I'd like to be able to make card suggestions or new combos or whatever.

You can already filter your sets (decks, inventory, tradelist, wishlist, even the full card listing - Games -> full card listing) by clicking on search & filter. You can select from many filtering options.