Generally MT doesn't work very well with Geocities or other such free services. There have been attempts to get MT to work with Tripod, but they have so completely screwed up Perl on Tripod that it really doesn't work (you can't access any of the core libraries that *ship with Perl*).
I will warn you, also, that when you're dealing with a complicated system like MT, the free services are not particularly reliable--they crash more often, you run out of disk quota more often, etc. Just a word of warning.