Can anyone recommend a good server/website monitoring tool? One that will email or even contact my mobile if there is a problem.

Cheers :)

If anyone knows of a server program to do this. Windows or Linux please let me know. I know about WhatsUp. But it is too expensive.

www.demarc.org
www.netsaint.org

I prefer demarc.

Have you tried www.qwkmon.net (http://www.qwkmon.net) ? Works well for us :)

Red Alert works well.