Everyone says that there is no second tier penalty, but I never see anything other than .com when I search, so I don't believe that. But just to be sure, if you are building a business ALWAYS get the .net and .org and others if you can afford it just to be sure nobody copies your brand.
.com is like the main one that everyone uses... but there are alot of people like me who use .net... i have 2websites with .net and 1 forum with .com... simply i get more people on the .net than .com, why i don't know... mostly all the people i get from .net are international : Europe/Spain... so on.
while .com has lowly registration and most of them are only from america.
Also, it really doesn't matter what your website represents. If you want to go to a website for a charity are you going to assume it's a .org or will you type in the .com?
Studies have shown that people will assume a website ends in .com about 99% of the time or more. You might save money by getting .info or .golf stare but in the end you'll pay ten times as much in marketing.
If your site is coolstuff.info, it's only a matter of time before the guy who owns coolstuff.com will realize you've developed a site on the .info. All he has to do then is develop one too and when your visitors accidentally type in .com they'll soon forget that your site ever existed.
Of course you can try your luck. I've only been doing this for 10 years. What do I know.