I want one of those markers, but since I cut my firewood at 24", I'd have to buy another wheel, and I'm too cheap to spend 35 bucks on such a thing. I use a 2' stick on a handle and a can of paint. Need something quick when cutting up hardwood limbs, otherwise you end up spending more time marking than cutting. The stick is also nice because you can "skip" over defects, rotten spots, etc.; whereas with the marker you have to watch to make sure the wheel is in the right position and stays there when you move it.
If the laser would work reliably in different positions, I'd definitely be interested in at least seeing one and how it's designed. A certain place that sells tools from China has what they call a "laser marker", says it mounts with screws, adhesive, or magnet. Basically a small laser pointer on a ball swivel, you'd probably have to adjust the laser to be at the mark either with the tip or base of the bar against the log to be consistent.
The one problem I have is that I'd want it to be on both sides of the bar, sometimes you have to cut the other way down a log. Something to fool with, might have to pick up a laser this weekend and play.
