Anybody has an idea whether changing Web hosting service has an impact on the PR? Will it be reset to nil or will it follow the site at the new server? Thanks.
It does not have an effect on PR as the engines go by URLs only. But make sure you are not sharing an IP with 100 people you don't know.
Sharing an IP is not a problem, if your hosting is changing from the UK to the US for example then this affects your serps.
Why is that mad4? I've currently got a dedicated server in the US though was looking at renting one closer to home (in the UK incidently) so I could afford to call tech support, though aren't as keen if I'm going to lose places. I'm not running anything particularly high traffic, but my sites have been growing and could do without disrupting them.
You need to host in the country that you want your visitors to come from. Search engines use hosting location to figure out where your site is.
yes mad4 is correct. if for example you use a US account then changed to a UK one, then your rankings on google.com might go down but your ranking to google.co.uk will probably go up.