i found an excellent page on how to block most pop-up ads and banners. it also helps save bandwidth and is updated periodically.
it works by adding entries to your hosts file (everyone has one wheter its *nix , M$, or Apple). Your computer by default looks to the hosts file before it contacts a DNS server to find an ip address for a web page. the hosts file entry has url's for thousands of ads and redirects them to 127.0.0.1 or 0.0.0.0.
instructions are simple and are are avalaible on the website.