Quote from brocklanders:
the best way is to setup a solution yourself and use a remote program to connect back to your desktop computer. There are plenty of secure ways to do this. One app that I really like for Android is Wyse PocketCloud. I don't recommend using unsecured VNC or RDP though but using SSH or a VPN to encrypt works pretty well.
I haven't seen it on a tablet but if it works as well as it does from a phone it would be a great solution for this. If you are going to buy an Android tablet wait until Ice Cream Sandwich drops later this year. It will bring together the phones and tablets and there will be a lot of new offerings once it is released. Eric Schmidt let it slip during a talk that it is scheduled for this Oct or Nov.