Ashlee Simpson likes to giggle. She really likes to giggle. In fact, it was hard to keep the multi-platinum-selling artist from laughing as she discussed her movie debut in "Undiscovered" in Los Angeles (insert joke here). But, make no mistake: The role was something Simpson took very seriously. Perhaps a bit too much...
 
"I was very dirty. I would go like a week," Simpson says of not bathing for the film. "Because I felt like the character didn't care about her appearance and I kind of wanted to feel that way. I shower normally!" (Laughs.)

"Undiscovered" centers on a wannabe singer/songwriter played by Steve Strait (the studly bad boy in "Sky High") and a model-turned-actress played by a misused Pell James. It allowed Simpson to star in a supporting role that didn't have the pressure of carrying the movie.

"I was looking for a movie where I wasn't the lead in it," the newly blonde Simpson says. "And a movie where I could go in and work with great actors."

(Her scenes with Carrie Fisher and Peter Weller must qualify for that last comment.)

Simpson's role as a struggling acting student wasn't that challenging this time around, but it hasn't been a deterrent.

"I love doing movies," she says. "So, hopefully I'll be doing more of them in the future. But now I have a new album coming out so I've been focusing on that."

That new album will be released in October, with the first single -- "Boyfriend" -- coming out a month earlier. Add a new tour to her schedule and Simpson is one busy girl. She seems to relish keeping active; she toured on the weekends while shooting "Undiscovered" during the week. How does she find the energy?

"I mean, for me playing shows is so much fun," she says. "Maybe I just get energy because I'm 20? It might all go down soon!" (Laughs.)

Another stop on Simpson's fall agenda is an appearance on "Saturday Night Live." One could argue she still hasn't overcome the public scrutiny caused by her lip-syncing incident last year.

"It hasn't been confirmed, but I would love to go back and do 'Saturday Night Live,'" she says enthusiastically. "It's not necessarily about revenge on the world, but for myself. I want to perform, but I'd love to act and make fun of myself as well. I was having voice problems, but I really learned that you can't go out the night before a show. You gotta be really strict, you can't eat certain things."

One thing she can do is get tattoos. She has allowed herself a new one after every major career milestone (first album, first tour). Her latest is the word "Love," scripted onto her right wrist underneath her palm. A reporter has to ask -- is it for anyone special in her life?

"No, it's not for anyone," she says with one last giggle. "It's like Spider-Man. I can shoot love to people."

Watch out, she's armed and dangerous.

"Undiscovered" is now playing.