Hot Logo is relatively new so I can't say for sure whether or not they'll pay out as stated, but nothing I've seen has made me feel like they aren't legit. This is my referral link which gets you an opening bonus:

http://hotlogo.net/p50429

Then it's just a case of judging logos and stating why you think one is better than the other. I worked out the rates and if it takes around 60 seconds per task which will earn you $0.40 minimum (on average), you're looking at $24 per hour. I'm sure there are limits to how many you can do per day, but I haven't hit that limit yet and I've done 9 so far I believe since setting up around 20 mins ago.

Worth trying for some extra cash!