Kim - do try the Huron Carol - I've been doing that for about 5 or six years.

I have an incentive in that I am performing every weekend from Thanksgiving to Christmas - primarily acapella carols - and a lot of times solo- and you get bored really fast if you only know a few and end up singing almost non-stop for 4 hours. So they get "brushed off" every year during the four weeks of rehearsals - then I try to learn a couple new ones each year. or at least memorize an "old" one so I can do it without cheat sheets.