Thanks for the feedback.  I figure if people are willing to trust Casascius coins and online companies to hold their Bitcoins, why not me?  But time will tell.  I would very much like to do split-key vanity address generation on demand though, so I will start looking at adding that as a feature.

Just the one prize for now.  I'm not BTC-rich, so I can only afford to give away so much...!