I found this:
http://www.cse.msu.edu/~alexliu/publications/Cookie/cookie.p...
here:
http://security.stackexchange.com/questions/7398/secure-sess...
And implemented it.
It was quick, cheap, and easy enough for me to assign a new token with most (if not every) request that required authorization/authentication. The only bits of info kept in the cookie were insensitive bits of data, so if a single token got cracked it wouldn't be a huge deal.