http://www.freezeyourfanny.com/  pre-reg price $25 through Jan 25th
 
Dave R. and I did this one last year, in 50-60 degree temps and sunshine --  and it's a very nice route, per our recollection...  So much so that, if the weather is nice enough, we're going to attempt to convince the wives to do the 40-miler on the tandems!  If it's deemed too chilly for them, we'll be riding it solo -- unless the weather is REALLY stupidly cold.

I wouldn't mind a carpool if I went, but he is too fast for me, so he would be stuck waiting an hour+ for me to arrive I suspect.