Abstract no.4

I'm so ridiculously busy these days that I've got no time for photos, so I'm feeling a little uninspired. So I've responded with an abstract photo for today (late in the day).

Any guesses as to what this one is?

Elsewhere... One of my photos from the recent DoLime Quarry visit is featured today as the Picture of the Day on the Powershot User web site. Please check it out and vote if you like it — you may have to click on the 'Today's Picture' link for the voting form to appear. (thanks!)