[Snorgle] You don't need to have your browser open to receive those blasted things but, to the best of my knowledge, you do need to be on-line (though I'm prepared to stand corrected.) They have been a recent phenomenon for me, starting to appear in the last week or two; I just 'x' them. I shall see if my latest virus/firewall combo stops them from appearing - only time will tell.
[snorgle] no, it's not spyware, it's just a new kind of mass-market spam which appears to use Windows Instant Messenger rather than email. (Although I've several times told Instant Messenger not to receive messages, an instruction which it cheerfully ignores.) Feel free to simply delete the messages and ignore them, and if you find a way of suppressing them, please post it here so we can all know ;-)
Mozilla Firebird + Linux. Haven't seen a pop-up in almost an entire calendar year. Mind you, it tends to cut down on the usability of cricinfo.com.... :)
No, its not the windows messenger spam, because I'm on windows 98. I checked on www.grc.com, and tested for that anyway, and nothing came up. It's got a couple of links to websites selling programs to spam people this way, which is quite interesting. One of them has a page explaining how to turn off your messenger service as well, so I guess they got complaints! I may try firebird..