I'm thinking that we're both so old we forgot to check the dates of the original post. We're responding to someone who is responding to a two year old thread.
Anyway, there are a lot of solutions for this today. No need for a jailbreak just to hijack PDF forms back out of iBooks. Not to say it wouldn't be a nice feature if you were already jailbroken, but probably not worth the trouble of jailbreaking all on it's own.
No criticism meant of Dminnici. This happens all the time; old threads rising from the dead.