I read a thread on a Linux forum about a Google application called namebench. Basically, it recommends DNS servers for you based on a bunch of speed tests it does. I hooked my N900 up to my netbook, ran namebench and have now amended my internet connection settings to use 8.8.4.4 (Google, as it happens...) followed by the o2 default one. (I left the o2 default one in there rather than the 2nd fastest recommended server to make sure I don't inadvertantly loose any functionality...) Just thought I'd post about it here as it seems to be a pretty nifty tool. It is available in the Debian repos so might be worth porting so we can use it natively, if any of the awesome dev people are interested...