If you have a Palm Pilot, you can download a free version of ePocrates, which can be quite handy. It’s like a mini PDR, containing all the pertinent information about drugs. You can select all the drugs you’re taking, and it will display the drug interaction precautions as well. Another nice feature is the insurance formularies. When installing, you select your insurance company, and you’ll be able to tell if the drug is covered by them.