Last month “I asked on Twitter”:http://twitter.com/manton/statuses/1035361474 for opinions on comma-delimited vs. space-delimited tagging. I didn’t get very many responses, but what I did get was pretty interesting.
Consensus: most people like commas and everyone likes Flickr. (The second takeaway here is that the service or app is more important, since Flickr uses spaces and everyone seems to cope just fine, even that 66% who prefer commas.)
You can see the “full report stats on Wufoo”:http://riverfold.wufoo.com/reports/tagging-report/.