Today's e-mailed question is a practical one:

I've been invited to a Halloween party and my fiancée and I want to go as something science fictional. What do you suggest?

I'm glad you asked! Science fiction films offer a rich vein of characters to dress up as. The secret is not to go with the usual -- to dig a little deeper and come up with something fun that people aren't expecting from you, or from anyone else.

With that in mind, let me offer two initial prohibitions:

Don't go as any character you cosplay.
"Cosplay," for those of you who don't know, is short for "costume play" -- it's what all those people who go to science fiction conventions dressed up as a Klingon or a Stormtrooper do. While there is nothing wrong with cosplay, if you've already got the Stormtrooper uniform or the Klingon head ridges in your closet, then you're kind of already known for that, aren't you? Halloween costumes are about doing something different. You show up as a Klingon and everyone's gonna go, "Oh, look, here's Bob in his Klingon suit. Again." Don't be that cosplay guy!

Star Wars characters are forbidden.
Because, come on. A little originality, please. Even the Slave Leia costume, the veritable gold standard (as it were) of geek woman desirability, is overplayed at this point. Going as a Star Wars character for Halloween is the nerd holiday equivalent of being the guy who goes to a concert wearing the T-shirt of the band he's come to see. Don't be that nerd holiday guy!

Now that we have that straight, here are some specific suggestions for you.

1. Bones
I almost put that Star Trek characters were forbidden too, but then I realized that should probably just be for the Klingons. And besides, I think this year is a fine year for people to recognize Leonard "Bones" McCoy, the most underappreciated of the top-billed Star Trek characters. Whether the old school DeForest Kelley version or the somewhat hotter new Karl Urban version, Bones is the gold standard in scifi characters with cranky horse sense, and besides, there's nothing more fun than saying, "Damn it! I'm a doctor, not a [insert thing here]!" for an entire night.

2. Buckaroo Banzai (or any member of his entourage, the Hong Kong Cavaliers)
In fact, if you were really awesome, you would get together with, like, seven of your friends and come to the party walking like you were in the ending-credits sequence of that film. Of course, it will help if a) you can play musical instruments as well as understand particle physics, and b) are as good-looking as Peter Weller in the mid-'80s. Also, remember to bring a watermelon. When people ask, "What's the watermelon doing there?" you can say, "I'll tell you later." And then never do.

3. The Thing
Go to the party dressed like you usually do. When people ask what you're dressed as, say, "I'm the Thing." When they say, "But you're just dressed normally," say, "That's the point," and then suddenly grab them, make your eyes go wide and scream "WHAAAAAAAA," like tendrils are going to shoot out of your mouth and go up their nose and take them over. First they'll be scared, and then, man, will they pissed!

4. Ellen Ripley
Actually you have four choices here. There's All-Business Ripley (Alien), Maternal Gun-Toting Ripley (Aliens), Bald Ripley (Alien 3) and Sexy Leather-Clad Ripley (Alien Resurrection). All are good, although, of course, some are better than others. Chest-burster optional.

5. The Machine Man (who is actually a woman)
This is the famous iconic robot from Fritz Lang's 1927 science fiction masterpiece Metropolis. This is a fun one because everyone recognizes the robot when they see it but very few people can actually remember where it's from -- it's iconic of the entire genre of film more than of its own film. However, do expect a few people to ask if you're dressed up as a sexy C-3PO, or the Statue of Liberty. Those people you can smack with your shiny metal gloves.

6. The humans of WALL-E
This will be perfect if you've been lax in the exercising department lately and/or have a lot of pillows around the house you can employ for costuming. If you're really committed, you can make it so there's a reclining lounge chair at your waist with fake feet in front of you while your real feet are covered underneath. Then it will look like you're lazing about chubbily on a floating chair. Don't forget your cupcake in a cup!

What? Some of you are still mad you can't be a Star Wars character? Fine. You can be a Star Wars character -- if you do something creative with it. Some examples: Singles Bar Yoda ("Size matters not, baby"), Han Trio (Three Hans doing a capella covers of the Meco disco versions of Star Wars themes), Boba Shemp (the bounty hunting off-brand member of the Three Stooges), Mon Mothra (rebel leader/50-foot insect) and, of course, Darth Waiter ("I find your lack of tip ... disturbing"). You get what I'm saying. The world doesn't need another Stormtrooper or Slave Leia. It probably could use a Darth Waiter.