Server Monitor Widget allows you to monitor any server running PHPsysinfo (http://phpsysinfo.sourceforge.net/). PHPsysinfo is very easy to install and is free!
Wanted to put up a quick update... The Multi version is still in the works. We are very close and should have it updated shortly. Given we still have the approval process time as well.
Last comment from Widget Realm was that the multiple server functionality would be added "shortly" ... that was in July. Given the fact that the current version 1.2 was released in March I would consider this being dead. What a pity, it really would become a useful widget if multiplie servers would be supported.