Yup
http://www.cubatravelusa.com/cancun.htm
I find it cheaper to book a package incl hotels in havana when you get to the seething piss artist mancunian accented shellsuited hell of cancun - just to make sure that you will get something to eat at breakfast anyway - makes a change form the standard coach trip to Chicken PIzza as the smarmy multilinguial Mex toothy salesmen call it
You wont need a visa for Cuba if yer EU or US and they wont stamp your passport, as you dont want to fall foul of the Helms Burton ( I think ) Bill if yer an ameriKan - but I think Euros are the currency of choice in Cuba now
Jamiaca is another back door to Cuba for ameriKans and theres daily flights too.