+5  A: 

After some digging around, I'm quite sure that it is not possible through the Flot API. Nevertheless, if you get really dirty, you could do it - I have published a modified version of one example which does it. View source shows the whole uglyness.

Alexander Gyoshev
So would it be accurate to summarize your approach as: 1) use tiny ticks on the axis so that they won't actually show up; 2) build the labels yourselves using custom divs with calculated absolute styling to make sure they get in the right place?
Greg Borenstein
It seems like this is very close to how many of the Flot internals work :)
Greg Borenstein
Any way you could wrap it up and submit it to them as a patch? (PS. Thanks for the answer; I think you're right and am going to accept it now.)
Greg Borenstein
yup, that's the idea. I've copied some code from the drawing functions - they'll need some modifications, but I guess I can submit it soon :)
Alexander Gyoshev
+1  A: 

Starting June 2009 there's flot issue 167 which is a request for this exact feature. Includes two implementations and some agreement from the flot author that it's a good idea.

Nelson