LogMeIn is a remote desktop tool I have been using for a while now. It works over the Internet. It requires an application to be installed in the computer you want to remotely access. You can access the PC from any browser with a Internet connection.
I have installed this on my tablet PC. I do not carry the tablet to work as my office is a bonded warehouse and it is not easy to get permission to take laptops in and out of it.
With LogMeIn I can access my tablet anytime. The service provides both an ActiveX and a Java component to access the remote computer. Based on the Internet speed on both sides it automatically selects the appropriate color depth. It can match the remote machine to the accessing PCs resolution. It works pretty well even with the slow 256Kbps connection at home.
Best of all they have a free version which satisfies most of my needs. Anyway if you are looking for a remote desktop solution that works with out having to bother about IP addresses, proxy/firewall/router configurations try out LogMeIn.