I don't generally go on about gear. I really don't. But I've been having too much fun with my last couple of hardware additions not to share. I am mostly using both of these for orchestral virtual instrument mockups. Though I can see either of them being pretty cool for other synth type sounds too.
Firstly, I've added a breath controller. Not the kind with keys on it, I'm not a real wind instrument player - just the type that you blow into and that lets you map your breath pressure to CC1, or 2, or 11, or whatever your particular virtual instrument uses to control dynamics. The one I got is from a company called TeControl. I lashed out and got their deluxe model which tracks and maps the tilt of your head and how hard you're biting on the mouthpiece as well as your breath pressure. As you'd expect, this thing is just great for woodwinds and brass.
Second, I got a thing called Leap Motion, that's been around a few years now. It's basically a USB motion sensor that you sit down anywhere flat, like on your desktop, and it can track exactly the position and angle of your hands as you move them over the top of it. The cool thing for musicians is when you hook it up with a program called GecoMIDI that lets you map those motions to MIDI controller data of your choosing. From there you can do pretty much what you want with it; just for basics, I've immediately found it to be really effective for putting life into sustained string patches. Set it up so lifting or lowering your hand controls the dynamics. If the patch has separate control for vibrato, set that to respond to moving your hand towards/away from yourself.
In both cases, it can get a lot funkier - depends what kind of controls your virtual instruments support and what exactly you want to do with them. I'm just using these tools with "conventional" sample libraries (almost exclusively EastWest) at present. Aside from some very clever stuff a fellow called Chet Singer did for Reaktor, I don't have any of the new generation of physical modeling instruments - if I did I'm sure I'd be even more hooked on what this hardware can do. But even with the older style of libraries, I am finding this pair of gizmos to be a serious time saver. Makes it so much easier, quicker and more intuitive to get the kind of expression I want into orchestral instruments.
Anyway, that's enough of a rant. For anyone who's working with orchestral sounds a lot and who doesn't have something like this happening already, I really recommend doing a bit of Google searching, there are plenty of Youtube videos out there showing what you can do with these things. Cross reference breath controls and/or Leap Motion with sample modeling if you really want to be impressed

Thanks for reading,
Bruce.