if you will own .co 99% of the people will first visit .com so it's a 99% chance you will loose visitors and thus clients, all domain extensions except .com are bad (except few of .net). have you ever seen a good company running with a domain that is not .com? me enthier.... people buy other extensions because they are available, you should go for a .com , and if not available all other extensions are pretty much equal in their low quality and the chance that people will remember them.
stick to .com - never really liked it as all your hard work just goes to the .com owner as .co is still new people would still visit the .com = like what happened with overstock.com and they still messed up! and if they did - I guess we will too.
No, it's not "cool" to own a .co domain. I donno why would anyone think, it's cool. Maybe for someone who lives in Columbia, because that's the ccTLD for it.