I’ve been finding myself exporting lots of Illustrator layers to PNG, and hunted around for a script to automagically do this for me. After some digging, I found this gem by Matthew Ericson that can take either layers or artboards and export them to individual png, pdf, jpg, or eps files. The site above also talks about ways to name layers so that some layers always appear in export (e.g. backgrounds that should always be in the image). Hooray for a smart, generous design community!
gtcomms.wordpress.com 
So handy, thanks for the tip!