Whoooo-eee! Whoooo-eee! Brgrgrgrgrgrggrgrgrgrgrgrrrr ... Geeks of a certain age know the sounds of an acoustic, land-line modem. My first modem was the Atari 830 - a 300-baud device with big rubber cups that you slammed your rotary phone receiver down into once you'd manually dialed the right phone number. You then had to be quiet while accessing The Wizard's Palace BBS, or your own ambient room noise would create line noise in the modem.

Data transmission via voice calls had its day with cell phones too, thanks to a protocol called CSD, or circuit-switched data. Back in the '90s, I would connect CSD calls at 9600 baud to grab my e-mail with Eudora. Because CSD uses voice calls, it takes from your bucket of minutes, not from any Internet data plan. It's just slow. CSD use pretty much died out with the introduction of much faster systems like EDGE and 3G.

I was amused and a little bit thrilled to find that Motorola's new personal navigation devices, the TN700 series, use a form of data-over-voice to make Google searches and get Internet information. This isn't old-school CSD, though, and you can't make whee-ooo noises into your cell phone to confuse it. It's a proprietary protocol developed by a company called Airbiquity with a very low transfer speed, only 800 baud. That's lower than good ol' CSD. But Airbiquity's aqLink works on a range of different networks with different voice codecs, and it doesn't require any involvement from the wireless carrier.

Airbiquity's solution leverages one of the strange imbalances in cell-phone plans today - most people have a lot more voice minutes than they ever use, but carriers are ratcheting up data prices. Much like SMS-based info services (such as texting GOOGL to search), this is a neat way to get info over your cell while saving money.