Here's the final installment in my series of columns about last week's Macworld Expo. It looks at products that amount to less than they first appear to be and a major update to a troubleshooting utility.

Less-than-useful technologies? There were several products at the Expo that featured innovative technologies and appeared quite impressive at first look. But, after some thought, I concluded that, if not useless, they were unlikely to be used much - at least not in their present version. Maybe after a few years of development, they could become practical. But they aren't there yet. For now, they were more like a birthday present you desperately wished for as a child -- but then tossed in a storage bin within days of getting it.

One such product is Livescribe's Pulse smartpen. At its core, it's a voice recorder in the shape of a pen, especially designed for recording audio in large environments such as a classroom. What makes it unique is that the audio can be linked to what you are writing with the pen at the time. This means, for example, that while you draw a formula in your biochem class, you are also recording what the professor is saying. Later, you can tap on the formula in your notes and instantly hear what the prof said while you were writing. I am assuming here that the device really works as well as it did in the Expo demos, which may not be a safe assumption.

Doing this requires special paper designed to work with the pen. Livescribe sells the paper at a minimum of $20 for four 100-page books. Coming soon, you will be able to print your own Pulse pages from ordinary paper -- via a color printer with at least 600 dpi resolution.

Your notes and audio can be transferred to your Mac for permanent storage, as the pen also acts as a scanner. For another $30, you can purchase MyScript, which attempts to convert your handwritten notes into editable text (I did not see this demoed, so I cannot comment on its accuracy. But with my nearly illegible handwriting, I doubt it would be of much value for me.)

As a technological achievement, it looks and sounds very impressive. And maybe some students will find it useful. But if you already own any sort of audio recorder (even your iPhone might do in many situations) and have a scanner connected to your Mac, you can already do much of what the Pulse does. Unless the linkage of the audio to your notes is critical, you don't need the additional expense of a $150-$200 pen and special paper. Regardless, I suspect that most users will soon tire of the Pulse and paper combo, deciding that it isn't worth either the bother to carry the stuff around or the continued maintenance expense of using it. Indeed, many students will prefer to enter their notes directly on a laptop, bypassing the entire need to transfer the material from one device to another. With a program such as Microsoft Word, you can even record audio while taking notes.

A second example in this dubious category is Microvision's SHOW WX. This projector, about the size of an iPhone, can connect to an iPhone (or most other devices with video out capability) and display a laser image of what's on the device. You could use it, for example, to project movies onto a wall or onto a piece of cardboard set up as a "screen." The image is always in focus and increases in size as you move the projector farther away from the screen. The image doesn't have the brightness or clarity of an LCD screen, but it's still quite pleasant to look at.

The main problem for me is, I can't imagine too many situations where one would want to use the projector. Yes, you could use it to show a video from your iPhone at a meeting (but not a Keynote presentation, as the iPhone doesn't yet provide this option). Still, for a business presentation, I would much more likely use my laptop, which already has a 15" display, often eliminating the need for a separate projector. Even if a bigger display were needed, there might already be a standard VGA projector available.

While there might be a few situations where the SHOW WX projector would be my top choice, they are not always predictable. To get the maximum benefit from the projector, I would need to carry the device all the time, something I am not likely to do.

Further detracting from its practicality, the projector runs on battery power -- with the battery lasting a maximum of two hours. This means, if I used it to watch a movie, the battery would often run out before the movie was over. 

One day, when the projector runs for 6 hours on one charge and is half its size and when its image quality is better and it can clip directly to an iPhone and when the iPhone can display Keynote or PowerPoint slideshows, it may be a product worth running out to buy. But it's not there yet.

TechTool Pro 5. I couldn't end my Expo coverage without commenting on a major upgrade to a popular troubleshooting utility. The folks at Micromat have started shipping TechTool Pro 5. For starters, the new version features a complete overhaul of its user interface. While this doesn't affect how many problems TechTool Pro fixes, it makes for a lot more fun to watch it work. TechTool Pro 5 does have some significant new features. Most notably, it brings back a popular feature dropped from TechTool in version 4: Trash recovery. If you accidentally delete a file, and you have Trash History enabled, you can undelete it. If you are in the market for a repair-and-recovery utility, definitely check out TechTool Pro 5.

Final comments. Beyond the products noted in this three-part series, there were many other worthwhile products -- from Ecamm's Bluetooth webcam to OmniFocus for the iPhone (to name just two) -- that I didn't have room to cover. It made for a great Expo overall. Clearly, the Expo doesn't need Apple, nor a major new product from Apple, to be a success. It merely needs vendors and attendees to keep coming. Without this, the potential end of Macworld Expo could become a self-fulfilling prophecy. Keep the faith and Macworld Expo will continue to thrive!