Ooh, I've had the plantar fasciitis! very painful! The paper suggestion is very good for strengthening! It can also be done with a towel (it's a little easier)
To help soothe the pain, try rolling your foot over a soda can or tennis ball. The can works really well, and it always seemed to make mine feel somewhat better. Anti-inflammatories (such as Alleve) help to reduce the inflammation that causes the pain, and also helps to heal the injured tissues. stuff like ibuprofen and aspirin don't do it though, they just mask the pain!
I'm also a big fan of Sauconys! They seem to be great for flat footed people.