Do you need full access to a work computer when you're away from it--controlling it as if you were at its keyboard, printing to its printer, transferring files to and from it, and so on? Then you'll want to try LogMeIn Pro2 ($70/year, 30-day free trial), an excellent way to remotely control your PC. With it, you can take control any of your computers from any PC or Mac over the Internet, using only a supported browser. You can sit at any other Internet-connected computer, controlling your main computer just as if you were sitting there.
Setup takes two parts, both easy: Create an account on the LogMeIn.com Web site, then install the LogMeIn Pro2 software on the computer you wish to control. Tell the software you want that PC to be able to be controlled over the Internet. When you want to take control of it, log into your LogMeIn.com account, and you'll be able to take control of the computer, using either a PC or a Mac. The computer you want to control will have to left on, of course, and running LogMeIn Pro2. For the best performance, it helps install any software that it recommends on the machine on which you're using a browser, such as a Firefox plug-in or a special piece of Mac software. But you don't have to do that. It still works, even without the special software--and since you don't always have the option to install software on somebody else's computer, that's a relief.
Once LogMeIn Pro2 is set up, you can run the remote computer in its own browser window. You may have to fiddle with resolution settings on the machine from which you're connecting when you're connected if the resolution on the machine you're controlling and the one doing the controlling don't match.
LogMeIn Pro2 also offers very sophisticated reporting about your control of the remote PC, including things such as what tasks were scheduled to be performed on it, what processes were running on it, CPU use, and so on.
There's also a free version of LogMeIn, LogMeIn Free, which lacks features such as remote printing, file-sharing and reporting. If you want only simple remote access to a computer, you can go with the free version. But if you want or need the paid features, you'll have to pay the annual fee.