I'm a little bit concerned... Sitemeter is set to ignore visits from my current IP address - I've checked, and it tells me what my current IP address is, and confirms that it's ignoring visits from there.
But since yesterday evening, whenever I'm logged onto my blog, Sitemeter is tracking another IP address from a different server, which is logged on for as long as I am and clicks out to all the same places I'm clicking out to.
Does this mean there's some sort of spyware allowing another site to track everything I'm doing? If so, does that mean I should immediately stop internet banking and paying bills from this computer, and go and spend a fortune on some sort of anti-spyware device? Or am I just being paranoid?
Update: I'm not sure that this resolves the particular issue I was worried about, but Esther has looked into Sitemeter and found that it allows a spyware firm to place cookies on every user's computer for advertising purposes. I'm not into being used in this way without my knowledge, so have switched to StatCounter. Thanks for the tip, Esther.