Max's suggestion is about the best you can do. And that feature is
unreliable at best - I've done it with my own name and seen "recent" postings
listed that are years old, while not listing some made within days of using
the feature.
The other feature that's been broken since at least Oct '09 is the
notification of responses to postings - a sad lack that creates a boat-load
of work in keeping up on where I've been, and who may need clarification of
something I've said. On a scale of 1 to 10 with 1 being useless and 10 being
greatest thing since sliced bread, I'd rate the whole thing around here (with
the exception of the people trying to participate) at about a 2.