I was running a Twitter client (servlet + Postgres) in a 64MB VPS not too long ago. There were about ~2000 active users.

Statically-rendered websites (Jekyll, Blosxom, etc.) would work fine.

Though having a weird port number on a blog URL would probably cause me to think twice before clicking on it, at least from a bare-metal Windows machine; it makes me think "botnet dropper".

You can run a whole LAMP stack on that.

EDIT: That being the 64MB.

even worse: 64MB of VZ memory is much less then 64MB of real memory, as VZ limits allocated and not dirty memory.