There's quite a bit of other great stuff out there for harmon trombone and violin specifically, and I wanted to give a shout out to a few other friends.
Pierce Gradone has written a hauntingly beautiful piece called Ficta that skillfully uses the harmon. The opening is especially effective in its use of blending the trombone and violin, and the combinations of formants is evocative of a high pitched accordion to my ears:
Pierce has written a ton of really great stuff for the Aeolus Quartet, line upon line percussion, Concert Black, and a slew of great stuff for trombone. Sadly (for those of us in Austin), he and his wife are moving to IL, where he'll be working on a Ph.D at the University of Chicago.
Below is an excellent performance of his work Brassploitation for bass trombone and piano, played by Darren Workman and Tomoko Kashiwagi. He's also written a solo for Martin McCain, who is the Trombone Professor at Texas State, and a new trombone choir piece for my group at UTSA. Check him out!
Next up is a piece by Ethan Greene an excellent composer also based in Austin who possesses the best head shots of anyone I know (Visit his website and you'll understand.) Ethan wrote a piece called Flying Fish for trombone, violin, and Max/MSP which is a really great work, and a ton of fun to play. Flying Fish is 'a sonic impression of "flying fish” fireworks' and will be featured in a new film by Allison O'Daniel, with whom Ethan has collaborated in the past. Here is the opening, which tastefully combines the pizzicato violin, trombone, and processing:
Later in the piece, Ethan uses the harmon to create a neat minimalist texture with the trombone, violin, and dense electronics:
Ethan writes a ton of really interesting, inventive music. One of my other favorites is For Candles:
"For Candles (2011), for four candles and live electronics, is entirely generated from the dripping 
wax of four lit candles suspended horizontally over contact-mic’d strips of glass. The drips are first presented without processing, revealing intricate accent patterns and polyrhythms between the subtly differing “metronomes.” Once a steadiness is established, the drips are then sent through delay lines whose timing is controlled by the rate of the “maestro candle”, and finally through pitched comb filters to create a four-voice waxen chorale. All processing is done in Max/MSP. Note: piece available in four-channel or stereo playback."
Another is Lissajous, a new work for vibraphone and electronics, expertly performed by Adam Groh, the new Assistant Professor of Percussion at Graceland University. Adam is not only an stellar percussionist, but is very active in the realm of electro-acoustic music. In fact, he has commissioned quite a number of pieces for percussion and electronics, and you can find out more about these projects here. He also has a really great blog!
Finally, after my last post I realized there exists a complete, superb recording of Mike Svoboda's Wah-wah etude online by Ben Zilber. Ben is a very fine trombonist who performs both orchestrally in New Zealand, composes, and has a number of electro-acoustic projects. Here is his great recording of Wah-wah: