A really excellent article from Bruce Schneier's security blog:QuoteApril 13, 2012Disguising Tor Traffic as Skype Video CallsOne of the problems with Tor traffic is that it can de detected and blocked. Here's SkypeMorph, a clever system that disguises Tor traffic as Skype video traffic.  To prevent the Tor traffic from being recognized by anyone analyzing the network flow, SkypeMorph uses what's known as traffic shaping to convert Tor packets into User Datagram Protocol packets, as used by Skype. The traffic shaping also mimics the sizes and timings of packets produced by normal Skype video conversations. As a result, outsiders observing the traffic between the end user and the bridge see data that looks identical to a Skype video conversation.  The SkypeMorph developers chose Skype because the software is widely used throughout the world, making it hard for governments to block it without arousing widespread criticism. The developers picked the VoIP client's video functions because its flow of packets more closely resembles Tor traffic. Voice communications, by contrast, show long pauses in transmissions, as one party speaks and the other listens.See more here (http://www.schneier.com/blog/archives/2012/04/disguising_tor.html)So now there's finally a way to have Plausible deniability for Tor... except in all those oppressive regimes where Skype is banned too!V.