The following paper is from Stanley's laboratory. It describes a technique to quantify pixel colocalization.

Lau et al (2004) A Syntaxin 1, Go, and N-Type Calcium Channel Complex at a Presynaptic Nerve Terminal: Analysis by Quantitative Immunocolocalization J. Neuroscience 24:4070-4081

Below is the link to the Nature STED paper that I mentioned on Tuesday.

Willig et al (2006) STED microscopy reveals that synaptotagmin remains clustered after synaptic vesicle exocytosis Nature. 2006 Apr 13;440(7086):879-80

Here also, is a review on this and some other techniques that you should read

Hell (2003) Toward fluorescence nanoscopy Nature Biotechnology 21, 1347 - 1355