For those unfamiliar with Paul, the movie stars Simon Pegg and his longtime co-star/co-writer Nick Frost as Graeme Willy and Clive Gollings, a pair of British geeks who travel to America to visit San Diego Comic-Con along with a slew of extra-terrestrial hot spots across the country. Ironically enough, they come across an actual alien named Paul (voiced by Seth Rogen) as they set off on a hilarious journey to get Paul back home.

The concept for Paul actually started on the set of Shaun of the Dead, when Simon Pegg and Nick Frost wanted to make a movie in a better climate than the dreary London weather.

"We kept having to re-do the record-throwing scene in Shaun of the Dead because the weather was so bad. (Producer) Nira (Park) said to us, 'Why can't you make a film somewhere where it doesn't rain?' Nick and I were like, 'Sure! It's this: There's two guys and they're in the desert and they bump into an alien and he's a normal guy and he's really friendly and his name is Paul.' We pitched this idea like it was a joke pitch."

Simon Pegg also talked about bringing director Greg Mottola on board to direct Paul.

We needed a director and enter Greg Mottola. Superbad was kicking around at the time, and I had seen The Daytrippers. Greg seemed to be the perfect guy to do it. Our original pitch for it was like [It was that] it's like Little Miss Sunshine with Gollum in it. We wanted an indie, road movie feel but, within it, there would be this insanely impressive special effect. That's why we hired Greg. He completely understood the script and he felt like a kindred spirit. Working with someone that you have that connection with is really nice."

He also talked about how the project evolved from that early idea on the Shaun of the Dead set, to what became Paul. One of the bonus features on the Blu-ray includes the original test footage that they shot, with Bill Hader providing the voice of Paul.

This Blu-ray also features an extended cut, which director Greg Mottola wasn't sure if he originally wanted to do for the home video release.

"It's something that, quite honestly, there's always a debate, artistically, about whether to do or not do. It's weird. It's weird to do a cut and work so hard on something and then do a longer cut. But at the end of the day, I felt it was more satisfying than doing cut scenes because there was so much stuff that we liked but felt was indulgent to keep in the theatrical version."

Greg Mottola also said there are a few extra bits at Comic-Con in the extended cut, along with things that just didn't fit in the movie.

"There is more stuff with Adam Shadowchild, which is stuff we liked, but we sacrificed for pace."

The director also talked about how they initially wanted to make the movie with a lower budget, although the effects of Paul demanded otherwise.

Simon Pegg also believes that the audience wouldn't go along with a puppet, and part of that stems from a controversial character from LucasFilm's past.

"I think people these days, they demand so much from reality. Think about how much we suspended our beliefs as kids. If CG doesn't look absolutely super-real now, people say it's rubbish. I think it's amazing, in a way, and I hate to bring this up, but it's a testament to how awful Jar Jar Binks was. He was actually an amazing achievement, to put a real CG character into a movie. It was just overshadowed by how terrible it was."

Paul hits the shelves on Blu-ray and DVD on August 9.