My ISP, Pipex, seems to be having problems with its DNS servers on a regular basis now, so I have to keep putting in new ones when they do. Most DNS servers provided by ISPs are limited to their own IP ranges now, so they don't work. I used to use Demon's DNS servers for years, but now you can't. So instead I guess IP addresses in the same range as those at my data center and hope they're running unprotected DNS.. luckily, most are.

This isn't a good situation though, but Googling for public DNS servers mostly brings up projects that provide free DNS hosting rather than simple resolution services. Which DNS servers do you recommend? This has also become a problem with FeedDigest, so much so that FeedDigest now runs its own DNS, which isn't ideal, but we don't have much choice due to ISP reliability.