.co is NOT associated with Columbia only anymore. It is fast becoming a globally recognised sld. Instead of .co being associated with Columbia it is actually associated with "Company". I would hang on to it for a while at least. .co's are being purchased at an alarming rate and might just be the next .com http://www.cointernet.co/domain/many-uses
This is BS - just a marketing hype - that is it.
Those investing in domains know this. Go do some reading on .ws and .tv domains. You will see the same.
.Co hype has already died. The only ones who got good .co domains are the ones who bought generic and trademarks related domains in the hope of getting traffic with typos.
Go to serious domaining forums and you will see this - try dnforum.com for a start.