I've seen these lights all over the place, but I couldn't interact with them. Any idea what they do? I know a little kid in Aleport said that they were "shinies" or something, implying they were some kind of treasure. Thanks. http://yfrog.com/mwlightsqj
They're gathering points. You can't interact with them because you're not a gathering class. Lights in trees and bushes are logging and harvesting points and require you to be botanist. Lights on rock faces are mining points and require you to be miner. I'm not entirely sure what the lights in Aleport are, since you seem to be able to fish anywhere there's water, rather than there being "fishing points".
Edit: Ah, spearfishing points for the fishing secondary tool. Learn something new every day. Does anybody know where you find points for the mining secondary tool? I know the bushes for the botany secondary... Edited, Oct 12th 2010 9:19pm by ChrisMattern
In Uldah's region, I find them in caves.
In Gridania, I find them along the rock face of the little streams you see (if it's in the water, its spearfishing, if its on the rocks, its quarrying).
When in doubt, whip it out. I mean your rock hammer, obviously.