Each week Ross Rubin contributes Switched On, a column about technology, multimedia, and digital entertainment.

With all the hoopla around the iPhone 3G, the finger has taken center stage as the input device of choice on the go. However, last week's column on the prospects of the Livescribe Pulse was actually the penultimate one on the subject of smart pens -- at least two alternatives have entered the market. Both are based heavily on reference designs from Israeli companies that have taken a different approach than Livescribe.

Rather than relying on a camera to read small dots on special paper, these pens work with practically any paper. And unlike the bulky Pulse with its ostentatious display, they are practically indistinguishable from normal pens and both come with software that can do a decent job of converting handwriting to text. The tradeoff is that some of the electronics have been offloaded to a small receiver that must be positioned on the paper, creating a two-piece solution.

IOGEAR's Mobile Digital Scribe, powered by Pegasus Technology, is a follow-on from a similar earlier product that required that the receiver be tethered to the PC. The Scribe can still function this way. In fact, when connected to a PC, the pen can be used to scribble (presumably for quick doodles, otherwise why not just use the keyboard?) just as its tethered predecessor could. Writing appears on an on-screen note that appears as soon as the writer begins to write, and the software can have these pages "float" on the screen as sticky notes..

Have you ever been sitting around and suddenly thought of the cure for cancer, or figured out how to build the world's largest hamburger, but you didn't have any way to get your idea down? Sure, you could write it on a piece of paper, but what if that paper got ripped, or blown away by a strong gust of wind? Well luckily, EPOS Technologies thought about all of this and came up with a solution: a digital pen which records your movements on a piece of paper, and then saves them to a USB flash drive for later use. The two-part combo utilizes the company's proprietary system of transmission which employs ultrasonic acoustic waves to help measure the distance and position of the pen, so apparently all you have to do is clip the flash drive to a notepad or related writing surface, and off you go. The whole wacky set-up is available for the bargain-basement price of $79, and should be available by the end of the year.