The Sims 3 for the iPod Touch and iPhone is a good, if not perfect translation of the PC version.
When you start the game, you have to create your Sim. You can adjust it's looks, and give it a personality that affects how you can interact with others.
After you are done creating your Sim, you are pretty much free to do whatever you want. You can go fishing, gardening, there is a good amount of stuff to do. But if you want to get far in this game, you need money. And to get money, simoleons(the currency of the game) you will need a job. There are plenty of jobs to get around town, and they each pay differently and have different working days and hours. You can get promotions if you befriend your boss.
Other than doing activities, you can make friends with other Sims, or make enemies. You can even get romantic with Sims and get married. Sometimes Sims will want you to do favors for them by doing something bad to another Sim, and you'll get money in return.
The graphics are fine for iDevice standards, but not the best. Everything is rendered well, but I have seen better looking games on the iPod Touch and iPhone.
The controls are okay. You use your fingers to control the camera when you're in a house. If you want to interact with something or someone, just tap it and a menu is brought up, giving you a list of options of things that you can do.
You also have stats, like hunger, cleanliness, etc. You should always keep on top of these stats, because if you don't, it will affect how you play. If you aren't having any fun, then you will be too bored to do any activities, like fishing.
There are also goals you can do. You don't have to do them, but if you want something to do, then, yes, you can do them. These goals include being well-fed for 3 days straight, to more bizarre like using someone else's shower.
Overall, The Sims 3 on the iPhone and iPod Touch is a good translation of the PC game. Even though it's not perfect, it still is good for when you want to play The Sims on the go. There is a good amount of stuff to do, and you'll play it for a while. I do recommend this game.