I have heard people mention about dry-hopping in the primary fermenter but i was never too sure about how it would turn out. Plus, since Im still using carboys and not a conical, I cant just drop my yeast so I guess it scared me a bit too much to try. But, I guess there is only one way to find out
+1 for the Brynildson method.
I dryhop near the end of fermentation (when bubbles are about 30 seconds apart in airlock). The warmer temperatures help with extraction, and you can add a good amount of dry hops without worrying about picking up grassy/vegetal flavors (you'll be racking off in a few days, anyway). Then I'll dryhop again in the keg, pull out the hop bag after 4 days, and then refrigerate/carbonate.
A keg for "secondary" is perfect, esp. for hoppy beers. That way you reduce transfers (oxygen pickup) AND you can purge the keg more effectively than carboys. Minimizing oxygen pickup is the key with hoppy beers. AND the beer gets to the glass quicker!