A classical effect which I found kind of an easy way of doing with the gimp. There's a filter in PS called ``Wind'' which would make this a lot easier... Actually there should be a lot more randomized effects for the Gimp.

Start With some text and Invert it.	I used a 70pt zaleskicaps in a 250x100RGB with antialias 3	c-N c-T a-I
Turn it 90 degrees and apply some shift and spread to it and turn it back.	I used Spread at 5 and Shift at 15, and did that twice	Eff/ Spr- Shift
Now make a new canvas and use the blend tool to make a mask like this one	I stretched it out to cover the whole text...	a-D L
Now Composite U-1 on U-2 with U-3 as a mask		a-C
Now a little Ripple and Shifting and not to forget Spreading	I did a Random Ripple with a period of 20 and amp. 5 and then Shift 5 and Spread 5 and finally blurred r=2	Dist/ Rip
Then a Gamma increase of red and decrease of blue gives this result, which is OK...	Red=4.0, Green=1.0 and Blue=0.1
But with a blur and a little Additive Brightness (BCG) we get perhas a beeter one.	I used Gaussian Blur with a radius of 2 and Additive Brightness 50	s+a-B
With a Lunarize and Invert of U-5 (if you left a spare) you get this.

The hard part of this is getting the effect in the third and fourth pictures. I'm working on a ``wind'' filter for the Gimp based on the Shift and Ripple filters (I'm not that good at math so I have to borrow :). Another thing missing is a ``curves'' liek tool where you level out the colors according to a curve that you have.