Sounds like a real awesome idea, honestly. I'm hoping that those lucky enough to receive them won't just pass them on for a quick cash in. Depending on the criteria I think this could be a good way of rewarding those that have contributed to the forum. As well as showing a little appreciation. I'm just wondering whether you need some help with determining criteria?

Features: Honestly, it would be awesome to make the coins somewhat unique to the person receiving them. So, instead of preloading it with Bitcoin I would suggest another thing such as stating why they've received it. This makes it a little more personal, and will increase the chance that these aren't just auctioned off to the highest bidder. So, for example if you were to reward someone who found a major exploit in the forum, and kept it all under wraps, and told you as soon as possible then I would consider that pretty integral to the forum, and you could print something like "Contribution to forum security". Probably a poor example  as I don't have the time right now to think of anything more creative, but you get the idea. The coin itself doesn't have to be designed uniquely, but could have a unique sticker depending on the person who is receiving it. I'm hoping these coins are going to go to those that have shown great contribution to the forum, and not just Bitcoin.