Anything other than a pipenet will be fingerprintable at some level. A pipenet is a network in which all links run at constant utilization, with dummy traffic (indistinguishable from useful traffic) sent over the links during idle periods. Pipenets are of course inefficient, but everything else is going to reveal some kind of signal distinguishable from noise at some level.
Since I have broadband, it would be nice to set aside a couple percent of my bandwidth for a pipenet (maybe over Tor, as well) and then leave the rest for low-security stuff.
That way I have a place for high-security low-bandwidth text to go if I ever need it.
