I love harvesting piggies, with the Animal Kinship VII skill and the Super Animal Harvest III upgrade card each piggy will give you 48 iMG and 8 - 40 meat all for only 8 energy (or free with Gurly Drinks). However it can be annoying trying to remember which pig you just petted or nibbled when there are a half dozen pigs on the street, however there is now a super easy way to harvest 30+ pigs with one Gurly Drink and no accidental feedings or renaming and little trouble remembering which actions you've done with which pig.
The trick? Use a Piggy Stick and set the radius to Very Tight, you will need Piggy Control Freak upgrade card to do this. What this does is it allows you to stand in front of the Piggy Stick and have all Piggies highlighted AT THE SAME TIME. As long as no piggies become unhighlighted and rehighlighted the order that the Piggies are displayed on the "Enter menu" WILL NOT CHANGE. So you can very systematically Pet and Nibble each Piggy twice and not lose track of which Piggies you've already interacted with.
This method makes Gurly Drinks ridiculously effective, I harvested a group of 30 Piggies with one Gurly Drink and got 1440 iMG and about 400-500 meat without using any energy at all!
Now this is the part where I ask you all for your help and cooperation. I just visited the top 40 Piggy streets as listed on this website http://resources.grelca.com/directory/piggy, and only 4 out of those 40 people had their Piggies set to a Very Tight radius. Given how annoyed I get when i select the same pig that I have already petted and nibbled 4-5 times in a row because none of the piggies on the street have unique names or I'm just not paying attention all while my Gurly drink buff is ticking away, I don't even bother with free roaming pigs on home streets anymore. With the Very Tight radius, as long as you can remember the position of the piggy you are working on (i.e. 2nd row 4th pig) you will not waste time clicking on pigs that only ask to be fed.
There is one tiny error that may mess you up once in a while when you first use this method, but it seems to only be caused by going too fast or lag and you eventually get used to it and can spot it easily. The error is that every once in a while the pig that you JUST nibbled or petted will not be on the "Enter Menu" and it will mess up your systematic pattern of harvesting by placing the next piggy in line where the piggy you just harvested was, however the next time you open the "Enter Menu" the missing piggy will be right back where he should be. The trick to noticing when a piggy is missing from the menu is to remember where the X to close the "Enter Menu" should be located (i.e. if there are 30 Piggies selected then the X button will be located on the 4th row in the 1st space, but if it is on the 3rd row in the 10th space then you have a missing piggy.) If you press Esc and then Enter again the piggy will be back or you can just keep harvesting and just make a mental note that you still need to finish that piggy.
I know that last part was probably confusing for most of you, so here is a "visual" example of this method, I am going to demonstrate on an extremely small scale here using 5 Piggies. We hit Enter and see the following Piggies in this order:
[Mario] [Luigi] [Princess Peach] [Yoshi] [Toad]
As long as all the Piggies remain highlighted together, they will ALWAYS be in this order.
Now let's assume that we have already finished petting and nibbling Mario and we have petted Luigi twice, we click on Luigi (2nd Piggy) a 3rd time but we see the option for Pet again. What is actually happening is Luigi is missing and Princess Peach is really in the 2nd Piggy spot like so:
[Mario] [Princess Peach] [Yoshi] [Toad]
It is really obvious with only 5 Piggies that 1 is missing, but with 20+ Piggies on the menu it gets hard to tell. So if you get 3 Pet options in a row, it is a good indicator. Regardless of whether you pet or nibble Princess Peach or just press Esc, the next time you press Enter the pigs WILL BE back in their original order (assuming they all remain highlighted the whole time).
That about sums up my thoughts and opinions on Piggy harvesting. I hope some of you benefit from this most likely TL;DR post.
ETA: Set your Piggy Stick radius to Very Tight.