I've been hit by a crapflood of trackbacks and it's a bit of a pain to cleanup in Movable Type (as I'm running it on Berkeley DB), so the easiest was to temporarily remove the trackback info on my page templates.
I'm planning to move to blojsom anyway, as soon as I'm ready with my new server (and I'll need some rewriting to map the current permalinks). I'll probably reactivate the trackbacks then, although they're not used much.
The new (virtual) server is hosted at bytemark.co.uk, everything looks really good until now but I haven't moved much stuff there yet. They give discounts for ASF members, and I've only had good experiences with their service until now.