[Update 2012-03-08] As discussed in the comments below, Apple broke the Bluetooth connectivity between Keynote and Keynote Remote in iOS 5.0 and 5.0.1. The good news is that they fixed it again in iOS 5.1 [/Update]
When you're wrong, you should admit it: When looking at Keynote Remote, I claimed that the connection between the controlling device and the device being controlled was only possible via WLAN. Turns out I was wrong: It also works with a Bluetooth connection.
Kudos to "Tulse", a user of Apple's discussion forums who posted detailed step-by-step instructions on how to set up a Bluetooth connection between an iPhone (or iPod Touch) and Keynote on the iPad. I'll reproduce them here:
- Turn off WiFi on both devices.
- Turn on Bluetooth on both devices.
- On the iPhone / iPod Touch, start Keynote Remote. Ignore the fact that it tells you that it requires a WiFi connection ...
- Set up a new connection: Tap on Settings and choose New Keynote Link. The four-digit code appears.
- On the iPad, start Keynote. Tap the wrench icon, select Settings, then Remote.
- If you already have a connection with your iPhone / iPod Touch (via WLAN), disconnect it.
- Wait a few seconds for the remote device to (re-)appear. Tap the "Link" button and enter the four-digit code.
- That's all. You can now control the presentation from your iPhone or iPod Touch.
(Actually, if you already have established a connection between the two devices over WLAN, you should be able to use it without any further setup once you've disabled WiFi and enabled Bluetooth.)
The trick in all this is that you need to disable the WiFi connection. From the description of Keynote Remote on the AppStore:
And if Wi-Fi becomes unavailable, Keynote Remote looks for a Bluetooth connection on your iPad, iPhone, or iPod touch.
What's confusing, as mentioned above, is that when you start Keynote Remote with WiFi off, it even tells you that it needs a WLAN connection - no mention of Bluetooth. On the other hand, the Remote setting in Keynote does mention both WiFi and Bluetooth. What's also confusing is that the pairing is done in Keynote, unlike normal Bluetooth pairing (e.g. with a keyboard), which is done in the iOS Settings app.
What does this all mean? The good news is that you can in fact remote control Keynote even without a WiFi connection. The bad news is that it still requires another iOS device which, as I mentioned elsewhere, can be a bit bulky.
P.S. If you'd rather use a more conventional remote, the Satechi Smart Pointer may be worth a look.