It was odd as the control pannel for our site was also loading slowly for me (which can only mean the problem was server side and not local to our site), but every thing looked completely normal when it did load. Other sites were ok so my ISP is an unlikely culprit, but I was waiting about 45 seconds for a page to fully load here for no apparent reason, so it seems.
Hopefully then it's local to my machine, which is an easy fix.