I am trying to reduce the writes to disk and in my social site I have a lastactivity table which is updated with the time() a user last used the site. It is currently MyIsam:
id int(7) PRI auto_increment
lastactivity int(10) unsigned
it has about 100,000 records currently. If mysql is restarted I can just populate it again from the last logins in the main user table. The machine has a lot of spare memory, but this table is frequently locked I imagine because of all the updates performed on it which would be better if it was MEMORY table type?