Mothers, you wouldn't let your sons grow up to be cowboys, would you? That's how the song goes, anyway.

So why would you let your daughters grow up to be Hannah Montana? Apparently, it's too late for that. Now there's a song that should be on the top of the charts these days.

Given the tween-beat frenzy around the fictional Walt Disney (NYSE: DIS) star, it probably should come as no surprise that "Hannah Montana costume" ranks at the top of the ten most searched-for Halloween costumes for the week ended Oct. 20, according to Hitwise.

It's usually sometime around October 1 that I first start seeing the Halloween costumes on the three- and four-year-olds in my neighborhood. A little girl on a morning run September 29 was my first sighting: a slinky tiger suit. It was especially awesome worn with one sleeve off. Last night, my son's friend Jackson came over to play wearing his Flash costume. My girls are equivocating; princesses, Tinkerbell, or the all-pleasing little girl combo, the fairy princess?

Yep. It's all about princesses, and mermaids, and of course, princess mermaids this year. It's Ariel's fault, naturally, she of the Little Mermaid movie re-release and the incessant repetition of "Kiss the Girl" on Disney Radio. As for my four-year-old, he wants to be a pirate. More specifically, a Pirate of the Carivean (his interpretation of "Pirates of the Caribbean Dead Man's Chest" -- frighteningly enough, he knows to put "Dead Man's Chest" at the end of the title every time he mentions it). Or maybe, he tells me, Diego (of Go, Diego, Go!, part of Viacom, Inc. (NYSE:VIA)'s Dora the Explorer franchise on Nick Jr.).

When I saw the Wall Street Journal's piece on popular Halloween costumes this year [subscription required], it got me to thinking: could I recommend stocks based on my considerable Halloween costume field studies?

Most obviously, The Walt Disney Company (NYSE:DIS) is a good bet for your Halloween investing dollar (is there such a thing?) It's princesses and mermaids and pirates, oh my! on the trick-or-treat path this season. But what else?