I have two blogs and they are both achingly slow -- on the website and within the admin (as in it take a few minutes for the page to appear)
I've had the sites for a while and haven't had this much slow down in the past. As far as I can tell, it started last night. I was slowly able to upgrade to 2.6.5 (automatic upgrade) earlier today and that seems to fix things completely, but now it is achingly slow again.
My hosting company is ValueWeb and the non-Wordpress portions of my site are normal speed (see http://www.typingmonkeys.com).
I'm not super techy, so I'm not sure what other information I need to provide.