Seth Rogen and Elizabeth Banks play the title characters, two platonic friends and roommates living outside of Pittsburgh. They share a shabby apartment, have a massive stack of unpaid bills, and get their electricity and water shut off. Fate intervenes when they attend their 10th high school reunion and bump into an old classmate (Brandon Routh of Superman Returns) whose boyfriend (Justin Long) is a gay porn star. Making and distributing a homemade porn works for that guy and subsequently seems like a good idea. Zack argues anyone would pay to see former classmates having sex on camera. Even if they only sold it to the 800 students in their graduating class at $20 a pop, they've have enough to work their way out of debt.

The next step is assembling a motley crew of wannabe moviemakers to help out. There's cameraman Deacon (Jeff Anderson of the Clerks pictures), producer/investor Delaney ("The Office" star Craig Robinson), and eager actors (real life porn stars Traci Lords and Katie Morgan, plus Smith fave Jason Mewes). The group devises a Star Wars parody called "Star Whores" and, when that doesn't quite work out, opt to shoot a java-themed skin flick in the mini-mall coffee shop where Zack works.

Of course, you can imagine the fun Smith has with this scenario. There's a scene where the characters brainstorm potential porn titles that have been inspired by real movies. It one-ups the famous Clerks moment where a video store worker rattles off a series of vile X-rated titles over the phone while a little girl and her mother watch in horror. The sex in porn films is spoofed here as well. My experience watching pornography is limited to a few times in college when I walked into my buddy's dorm room and found him playing adult movies on his VCR. (Total viewing time for me = about 6 or 7 minutes. I could stand no more. They offended my cinematic sensibilities.) Still, that's enough to know that the sex is cold and almost clinical, full of fake over-the-top arousal, ham-handed dialogue, and cornball scenarios designed to provide gratuitous excuses for rampant fornication. Smith's deviously dirty mind finds many opportunities for humor in the sheer cheesiness of porn, and he mines many big laughs from them.

That alone would allow Zack and Miri Make a Porno to be a rowdy good time, but here's where it gets interesting. We come to realize that Zack and Miri are in love with each other but have never spoken openly of their feelings. Their homemade porn movie is supposed to culminate with them having sex. Both are nervous about it, and their big moment comes with a twist. For all its hard-R dialogue and sexual humor, Smith's story is really concerned with the difference between making love and merely getting your rocks off. Zack and Miri go in assuming that their on-camera moment is a technicality - they need money and more shagging equals more potential profitability - but the act changes them because it means more than they are willing to admit.

That's right - this is, at heart, a love story. And a good one too. Smith is one of the most surprisingly multi-dimensional celebrities we have these days. The guy who celebrated his own slackerdom in Clerks went on to become a shrewd businessman who makes movies, writes books, sells merchandise, and operates several websites. The man who zinged the Catholic Church in Dogma has described himself as being a faithful follower of Christ. And the guy who inserted the most disgusting anal sex joke imaginable into this film is actually a romantic at heart.

Smith's tender side is nicely brought to life by Seth Rogen and Elizabeth Banks. In fact, I think this may be Rogen's finest screen work to date. He's totally believable as a horny, just-barely-employed lay-about, yet he also completely sells Zack's deep, unexpressed love for Miri. The later scenes, which move slightly away from the raunch and more toward the interpersonal, are particularly effective. I honestly cared about whether this lug would get the girl. That brings us to Banks who, with her other performances in W. and Role Models, is officially "having a moment." We're seeing an actress right on the cusp of becoming a star. Banks has the kind of vulnerability and likeability that makes you want to follow her wherever she goes, whomever she chooses to portray on screen. The chemistry between her and Rogen is fantastic (they previously worked together in The 40 Year-Old Virgin). She's drop-dead beautiful in an approachable, girl-next-door way, yet she can also comfortably drop a few F-bombs with the guys - the perfect female lead for a raunchy/sweet comedy like this.

I don't necessarily think that Zack and Miri Make a Porno has anything new or groundbreaking to say about either love or sex. That's fine by me. It is, if nothing else, an original approach to the material. I get frustrated by many of the love stories and romantic comedies that Hollywood feeds us these days. There's something fundamentally generic about them. (For proof, look at any movie starring Kate Hudson and/or Matthew McConaughey.) Zack and Miri finds a love story in a most unlikely place, which makes the romance that much more romantic while still leaving plenty of room to indulge in the potty mouth. I call that a winner on all sides.

( 1/2 out of four)

NOTE: Be sure to sit through the end credits for a special coda.

Zack and Miri Make a Porno is rated R for strong crude sexual content including dialogue, graphic nudity and pervasive language. The running time is 1 hour and 41 minutes.