the best mobile survey sites

i also have tried many, many survey apps for my iPhone and there are a few that i make decent money with. here are my top 3:

1.ipoll--this one has 'missions' that could involve visiting a grocery store, bank or gas station. you do frequently have to take pictures of specific products on the grocer shelf and occasionally a video or audio recording of your impressions as you are shopping. its easy and the pay is pretty good. i always check it when i am out shopping to see if there are any missions while i am already out and about. they do credit and pay SLOW--some jobs show pending for months but eventually get credited.
http://bit.ly/pSgd31

2.field agent--this one mostly involves going to a specific retailer and searching for a specific product. you almost always have to take photos too. once you claim a job you do have a time limit, typically 2 hrs to complete the assignment. they are sticklers and will refuse a job if you don't follow the instructions exactly. you get credited quickly though and can cash out to paypal. they pay fast and my paypal is usually credited within 24hrs. https://itunes.apple.com/us/app/field-agent/id

3.1Q--i just discovered this one. they ask you ONE question, yes just one, and you instantly get $1 to your paypal account! super easy but so far i have only had 5 questions from them in a few months time so its pretty infrequent. https://1q.com

--do you have any worthwhile sites that you use to earn a few bucks?