I have a BIG COMPLAINT regarding the NEW requester named "hostflower". HE SAID I DID AN EXCELLENT JOB on his assignment "Find whats inside - Bonus Opp" (he answered soon after I submitted my results), but didn't want to pay me immediately (REJECTED TO PAY). He offered me to finish some additional work for him and get bonuses (extra $23), so that he could, allegedly, pay me later all at once. I mean...hmmm!?!? I wrote him that I would like to be paid immediately for the work I've done, which is normal and standard for the Mechanical Turk, and that I will later consider doing that extra jobs for him. But, he didn't answer anything since, and I doubt he will. He owes me $2.40, which means a lot to me, 'cause I am a newbie and don't even have $10 on my account yet. Anyway, if he contacts me and gives me that money he owes, I will let you know. By then, BEWARE of hostflower!
Never download anything at MTurk. Very few HITs actually pay a bonus unless they're from reputed requesters who've been around since some time. Most of the high paying HITs are scams, better to work on low-paying ones which at least pay and don't end up getting rejected. Check requester reviews at http://turkopticon.differenceengines.com/ before working.
Hostflower has rejected me before. Most hits that pay over $3 are scams. The person above me was right, don't download anything. I did the hit "download yahoo toolbar" and was told I did not do it when I did and got rejected. I've also downloaded a game try-out thing from a requester before and it would have put a nasty virus on my computer if my virus protector had not caught it.