You say wait 3-6 blocks -- which makes sense for large transactions, but are there cases where 1 blocks have been getting reversed? Is this happening now because some parts of the network are on stale or diverging info?
https://bitcoin.stackexchange.com/questions/2170/how-often-f...
edit: I guess my point is that if you're selling coffee and making 100 $6 transaction, going 1 block deep probably isn't a big deal. If you're selling one car a month, you might not want to risk the small chance of an orphaned block -- but a one hour hold on title is a whole lot better than waiting for a check to clear.