Slick published a interesting review of available practical solutions for online anonimity. I listed below the summary of the solutions, by usage type:

• Web surfing: Tor  and Anonymizer. Tor uses a chain of onion router to transfer the data. Tor security is good but it’s rather slow. Anonymizer is a paid web surfing anonymizing program that routes one’s data via an encrypted SSL chanel.
• Access unsecure computers: Sandboxie and  “Live” Linux distributions. Sandboxie is a virtual sandbox. Data flows in both directions between programs and the sandbox. During read operations, data may flow from the hard disk into the sandbox. But data never flows back from the sandbox into the hard disk. The lived Linux distributions offers the same kind of security: Nothing is written on the host disk.
• Anonymous p2p:  Ants and Mute. The communication between peers is secure with those applications but they are much slower than open p2p applications. Another hybrid solution is Azureus (the bittorrent client) on top of the i2p network.