Recommendation of anonymous proxies source?

Hi,

I am using the manual proxy pool way of anonymizing as shown here:

http://community.screen-scraper.com/anonymization_via_manual_proxy_pools

And I am getting a list of proxies from here:

http://www.textproxylists.com/proxy.php?anonymous

However, when I filter them for 7 second connection timeouts as per the example, I end up with only around 30 usable proxies out of a list of around 900 servers :-S

I am wondering if anybody can suggest me a better source for getting a list of good anonymous proxies.

Many thanks,
boga