Any pit in a high school marching band in Texas has several of those going at once. As a band dad, I know how to pack them, disassemble them, assemble them, etc., but I leave the playing to the professionals (i.e., the high school students).

When they have ensemble competitions you get some really awesome music that highlights the instruments with keys (vibraphone, xylophone, marimba, etc.). One of the neatest ones last year was three people playing a marimba; the pieces "progressed" through the scale and the players had to move around it kind of like a conveyer belt.... at first when the player at the end ran out of high keys, he simply walked behind the other two people back to the low notes and picked up, but eventually they started walking around the other side of the instrument and played it backwards, so to speak, on their way back to the low notes (hard to picture from the description perhaps).

Here's a good example of what it looks like in the high school solo and ensemble competition.

(although that might be college level; I'm too ingnorant to know!)

I played percussion in high school, and a friend and I were pretty good on the bells and vibraphones. Our senior year, the instructor had the band play a piece that specifically highlighted our mad skillz. If you have any experience with the piano (and we both had years of experience), they are pretty easy to learn.

/me was a champion marimba player at the state solo/ensemble competition Doohickie referenced.