I've got a few 30-second samples I did for some Flash files. Nothing terribly fancy but you can see what an ebow sounds like.
I've been messing with one for 20 years or so and really like it. It's tough for most people to get the hang of em at first but it's worth the effort I think. If you can find a used one I think the old chrome plated ones are easier to use. The string spacing is different now and I think they've made it a little smaller. The old one fit my hand better but maybe that's just me because I'm 6'5".
$150 would be pretty steep. E Bows are very cool but very limited. If you want infinite sustain it is either an Ebow or the special sustaining pickups which I believe do the same thing.
Tex, I think what you may be referring to is called the Sustainiac. It's pretty cool too. I don't think the sound is as nice as an ebow but it's more flexable in that you can play chords and whatnot. One thing that's neat is that you can play harmonics clean and make them sustain forever. They have some nice samples on their website:
Another ebow-like gadget was called the Gizmotron. One of the guys in Godley and Creme (I think they both used to be with 10CC) invented it. It actually was mechanical and had 6 little rollers that sat above your guitar strings. You'd push down a button and the roller/s would engage and more or less act like a violin bow. Sounded almost just like an ebow. They were only in production a short time I think. I don't know if anybody is currently producing a retro model. I think Jimmy Page plays one on the beginning of "In the Evening".
I hate guitar synths (or any other kind of synth) but I've often thought that a good use for one would be to use a sampler with them to sample ebow's sound and then be able to play it back using chords, harmonics, or whatever, just like playing regular guitar. I think some sampled harmonics would be cool too as you could then play harmonic chords and stuff.
Nice sound darkman. It's a shame so many people don't mess around with one long enough to really get the hang of what they can do. And then, you have to work like mad to get one to sound like anything on a single coil pickup guitar. If they'd use a Les Paul to begin with they'd be much happier.