I use EMS Free Surfer Mk II, possibly the best pop up blocker I've come across. Download it
here. It features a "Natural" mode, which blocks most annoying pop-up ads, and a "Strict" mode which blocks ALL pop up ads. It also features a nifty little add-on that automatically clears your cache, cookies, recently downloaded files, whenever you ask it to, or whenever you have it scheduled to.
The following are spyware/adware scanners/removers
You can download SpyBot: Search and Destroy
here.
You can download Ad-aware 6.0
here.
I would recommend downloading both Spyware/Adware programs.
Spyware Blaster blocks all annoying bad ActiveX installation prompts, but allows the good ones through. Download it
here.
I've also used
WebWasher and
P.O.W, both of which are alternative Pop-Up blockers.