maybe oversimplifying things, but since you want just a moderate lvl of security, but ease off use just make a small app that generates the key on a trusted server, then encrypts it with symmetrical encryption, send the bitcoin address, secure delete it and then distribute the encrypted key along with a portion off the key so than whenever n out of m of the recipients join their parts there's at least one full copy off the symmetrical key.
and another app that receives such parts and outputs the bitcoin key.

that way you just have to trust the server in which the apps reside and generating the key is only a matter off imputing parameters of n, m, and delivery method for each member's parts and data.

and receiving the key will be a matter of imputing one copy of anyone encrypted data, the minimum amount off decryption fragments and where to deliver the key

and that way as long as the same code is running you don't even need to use the same server for getting the key back (although both will have to be trusted)

edit: after goggling i realized my solution was already posted somewhere else, along with another great one:
http://stackoverflow.com/questions/1719376/how-to-encrypt-something-so-that-can-be-decrypted-using-any-two-of-three-keys
the checksum one is great for your intention in my opinion, along with the best rated one (incredibly similar to mine)

sorry for the edit, but i rushed to post