If you use a very small workflow, it creates a task automatically.
If you send a mail to (e.g.) task@myserver.com and you enable the "accept incomming mails" on your tasklist, it should work as well...
the other alternative (most logic one actually) is talk to the list using XML with the existing webservices...
open IIS, goto your site-collection. I cannot find it back right now, but it exsists anyway... somewhere :-)
It can't be that hard to write it yourself anyway... several people have done it before.
good luck