I got this Belkin switch (
http://catalog.belki...oduct_Id=134802 ) . They are supposed to be used for 2 PC's, and have 2 lots of PS2 inputs however you can leave them and just use it for monitor switching as long as you plug at least one of the PS2 sockets from the PC into it (as it draws power from the PS2 port on the PC)
I decided to dish out the money risking the fact that it may not work without 2 PC;s or that it would not support the Xbox VGA output but i can safely say that it works absolutely fine and is switched using the keyboard. HOWEVER, the PC must be on for the switch to work and the xbox output to be visable, since the switch is powered by the PC. This is not a problem for me as my PC is on 24/7 but it may be for other people.
The switch is sweet quality, it came with properly inbuilt fully sheilded cables and supports pretty damn high resolutions. So if you want High Quality you should check the belkin range out ,
http://catalog.belki...s?Section_Id=56TNTrulex : On a side note, have you considered that it may be your cable? Most VGA extension cables are shit quality you have to actually know what you are looking for to get HQ cables.