The Java Servlet Specification 3.0, section 7.1.3, defines a fallback mechanism for maintaining a session with clients with disabled/unsupported cookies by rewriting urls.
This mechanism however has a number of drawbacks listed here:
http://randomcoder.com/articles/jsessionid-considered-harmful

The above Link also contains an example of how to disable url rewriting using a servlet filter.
Switching url rewriting off in lift would be a nice feature for many Lift Users.
This could for example be achieved by adding the functionality described in the above link to the LiftFilter and
making it configurable in LiftRules, e.g. like this:
LiftRules.jsessionUrlRewriting = false