I wrote previously about the open source project Tor in Tor: Anonymity Comes of Age. Now there is a mozilla browser that integrates Tor called Torpark. eWeek reviewed it and like what they saw in "Torpark Makes Anonymous Web Surfing Easy."

The browser automatically connects to the Tor network. The review said Torpark ran smoothly with only slightly slower than normal performance. The software can even be run directly from a USB drive. But that does significantly slow down page display.