I've only been working with a violinist this week, I've done minor bass pieces to get started, and we began to work on Prokofiev's first violin sonata (we both love the composer, and it felt more interesting than, say, Beethoven's fifth). The piano part is quite easy technically (especially the first movement ; haven't tried the allegrissimo together, looks quite harder though), but demand that you listen very carefully to the violin's mood, so I found it was a fitting way to start.
It seems I tend to rush a little too much, and play a little too loud sometimes... However I'm surprised to see it's not that hard to keep the rhythm. There's only two of us yet, so it's hardly a challenge I guess. A flutist should join us later, and I think there's something for piano / violin / flute by Debussy he wants to try, though I have yet to hear or read it.
It's fun, I definitly regret not trying playing with others sooner ; I also feel very lucky to work with a skilled violonist, as she hardly makes any mistake and can cope with most of mine (though she sighs *heavily* when I rush...). The Prokofiev piece is quite dark (and without the rhythmic ferocity his piano solo works have it seems), but I'm not depressed with it - yet

It makes the violin nice to hear, I can't stand some of this instrument's high pitched sounds... We tried a few easy Mozart's sonata, and I'm sad to say I dislike the way it sounds on the violin. Is it something you get used to (and eventually like) with experience ?
I have a question that might, or might not, be related ; do some of you feel like they got stranded on a desert island when they don't have a piano ? I do (I mean, you get those moments when you want to play NOW, and not being able to is just terrible, so terrible you have to get home quick and get your fix). My electric piano, though easier to move than the real deal, is not something you can, say, bring with you in the park on a sunny day, or while on vacation in the Alps (or even take at work to chill during coffee break !). Like I said earlier, I dislike most other's instrument tones above C5, so I guess there's no point in learning, say, the flute... How do you manage this ? Is there some kind of inflatable piano ? A folding piano ? An easy-to-make-wood-carved piano ? A theremin-like piano (included in your mobile phone !)?