I'm getting ready for a conference trip and have finally gotten around to getting a bluetooth presentation remote. The remote I purchased is the Sony VGP-BRMP10 Bluetooth Presentation Controller. The VGP-BRMP10 is a bluetooth remote that includes all of the functionality of a bluetooth 2-button mouse. It has a trackpad with a "scroll line" on its right hand side that emulates a scroll wheel. It has two mouse buttons (left and right; too bad for us Unix 3-button types, but really that shouldn't be necessary for how this device is used). It has next and previous slide buttons that send "page up" and "page down" keycodes. It also has a start/end slideshow button that sends F5/ESC (I'm not sure under which circumstances it sends which). It comes with a manual and two AAA batteries (the packaging says that these should last for around 14 hours); no bluetooth USB dongle, so you'd better have one or have a machine with built-in bluetooth.
So, how does it work with a Mac? Sony's site only lists compatibility with Vaios, though the box has a Windows XP/Vista badge. I tested it on my 1.33GHz 12" Powerbook G4 (I like to travel light) with built in bluetooth. I used the Bluetooth Setup Assistant to set it up as a mouse and this went without a hitch. The Keyboard Setup Assistant also ran, but I don't see how that would be very useful, so I just closed that window. I then used the mouse system preference pane to set the trackpad speed.
After that, the remote works almost perfectly. The only thing that doesn't work is use of the "slide show" button to start a slide show (I tested it in Adobe Reader, as I generate my presentations as PDF using LaTeX, and also in PowerPoint). However, that button does work to end the slide show (it seemed like I had to press it twice with PowerPoint, though). Since you have to plug your laptop into a projector anyway, this is not an important feature. It would probably be possible to get it to work with some keyboard remapping software (which, for all I know, is built into OS X; I just haven't wanted to spend the time to play with this).
Ergonomically, the remote seems fine to me. It's not very smoothly shaped, but the large battery compartment makes the back of the device fit nicely into the curve of your fingers with your thumb positioned to hit the buttons or use the track pad.
Amazon/PC Universe has been selling this remote for $80, which seems a very good price indeed for the features it has. The only thing it's lacking is a laser pointer, which isn't a big deal for me, since the cursor is visible in Reader and I think that's a better way to point anyway (for one thing, it stays put where you leave it, so nobody can tell if you're nervous).