I would love to start a business developing, marketing, reselling, and investing in analog devices for computers.
My brother Kevin had one of these and I had to go and copy him immediately and get my own.
Griffin Technology’s PowerMate. 
It is a programmable controller with rotate and click (or click and rotate) only.
It is sturdy, heavy and glows. How cool.
I’ve already touted the benefits of multiple monitors and the advantages of less task-switching and this is a great extension of that concept. If you are like me and listen to music at work, you are constantly pausing, removing headphones, answering the phone or speaking to whoever walks up. Even though I had a dedicated spot for my music (now iTunes mini), I’d still have to drag my mouse over there and precisely hit the pause button. Now I just reach over and pound this device and it pauses for me. Same for volume. Whenever a song comes on way too loud I can swing the knob around and save my ears from damage.
Plus, computers have never had good “controls” for things like volume. Remember the old CD players for computers that had round volume knobs and you’d have to circle your mouse around it to turn it up or down? Having a real knob makes so much more sense.
Just to round out my product review, you can program the controller to be application specific too if you like and make it do whatever you want — zoom in photoshop for instance. But I like mine to be singularly purposed. Pause, Play, Volume Up, Volume Down, Previous Track (click and turn), Next Track.
But I’ve been thinking about this space for years. I have a brand spanking new Cisco 7940 Series corporate provided IP Phone on my desk. IP as in Internet Protocol, so how come I can’t open Outlook 2003, click on a contact’s name and hit a button on the handset to dial? It is physically connected to the same switch as my computer, but knows nothing about it. Annoying to be so close, yet so far to having this stuff integrated in a useful way. A SIP based phone that was 10% soft and 90% hard/real would be better.
Another idea I’ve been sitting on. I would like a key-fob, perhaps as part of a two factor authentications that would work via bluetooth and sense my presence in IM (and other attention necessary applications). And I’d like most of my IM friends to do the same. IM would be more useful if I could really tell if somebody is there or just got up to leave, but hasn’t hit the 5 or 10 minute timeout on “away”. I should be able to stand up from my desk and walk away with my computer remembering to: 1) lock the screen so nobody comes up and reads what I had on my screen 2) pause the music, video whatever 3) set my IM to “away” 4) start indexing for my desktop search tool, Copernic 5) start forwarding copies of any emails marked urgent to my mobile device, currently an Audiovox SMT 5600.
All of this is completely technically achievable today without inventing anything, it just needs integrating.
you should really mention ituneskeys in here as well. i’m really glad you pointed it to me as well. i’ve emailed him to possibly become a beta-tester/developer for it also. it’s a *must* for the powermate as it limits you to a single ‘openfile’ command which also limits response time due to its overhead of not residing in memory – whereas the sendkey commands (hotkeys) allow you to overcome this.
*awesome* feature for ituneskeys is the ‘find missing artwork’ option which will download and install the missing coverart automatically in itunes. it’s still a bit buggy but well worth it, hopefully it will continue to evolve in the right directions.