Liberating the bedroom aka Getting the Boys to Sleep in Their Crib

Ok. So the boys sleep from 11p til 7a now.  The caveat being that they sleep in their swings...in our room.  We do not have a very big room & 2 swings take up a heck of a lot of space.  They will also sleep with no complaints in our bed when we have our bed heaters on (think electric blanket under you instead of on you.)  I figure they'll sleep in their crib if it stayed warm like our bed.  Obviously, they do not make crib size bed heaters so I researched and researched and I found this:
http://perfectlysafe.stores.yahoo.net/81202-bedwarm.html

I think it might be the answer to our prayers.  Plus, I'm thinking about getting one for Mini, too, cause her room is freezing.

UPDATE:
I put the bedwarmer on Mini's bed.  Though I cannot tell the difference when I put my hand on it I can tell that it makes a difference.  It is 62 degrees in Madi's room right now yet she is warm with just her lightweight footie sleeper on.  Her hands are warm (this is how I can tell, before her hands were cold.)  Well worth the $8 investment.