With thousands of different choices, finding the best investments gets more challenging all the time. One thing you can be sure of, though, is that while you're searching for tomorrow's winners, you're bound to come across some pretty bizarre offerings along the way.

Investments that just didn't catch on
In order to make sure they stay on top of the most current trends, financial institutions keep developing a constant flow of new investments to make available to investors. The hope is that they'll gain a big enough following to make them viable profit-makers.

In their search to find the hottest niche, though, financial institutions don't always get it right. I've found four unusual investments that thus far haven't managed to attract a big audience.

Funds that focus on particular countries around the world have gotten extremely popular. But drilling down even further hasn't proven to be successful for this fund, which only includes companies with headquarters or significant operations in Oklahoma.

Because the state relies heavily on the energy industry for its business prospects, more than 60% of OOK's assets are invested in energy stocks. But the fund has also gotten a lift recently from Dollar Thrifty Group (NYSE: DTG), one of the biggest gainers since March 2009's lows. Even with all that going for it, though, OOK has only $12 million in assets, and for the most part, a simple broad-based energy ETF should come close to matching its results over the long haul.

2. B2B Internet HOLDRS (BHH)
As a concept, this fund doesn't sound too strange: buy companies that provide Internet-based business-to-business solutions. Where this fund falls short, though, is in its execution.

The key lies in the structure of HOLDRS. Regular ETFs typically track indexes that can replace companies when they're taken over or go out of business. HOLDRS, though, doesn't have that flexibility. As a result, this fund holds just two stocks: Ariba and Internet Capital Group, with fully 89% in Ariba. A similar fund, Internet Infrastructure HOLDRS (IIH), has 80% of its money in Verisign (Nasdaq: VRSN) and Akamai Technologies (Nasdaq: AKAM).

Some of these companies have a lot going for them. In particular, Akamai has consistently delivered analyst-beating earnings, while Verisign is poised to keep providing technology security in an increasing dangerous online world.

But if you want those companies, go ahead and buy them. You don't really need HOLDRS to help you. B2B Internet HOLDRS has less than $4 million left invested, so it's clear nearly everyone else has already made the switch.

3. Claymore/Sabrient Stealth Index (STH)
Here's another fund that seems to make sense on its face. The idea behind this ETF is to buy companies that don't have a huge following on Wall Street, with no more than two analysts tracking the stocks.

Combing through undiscovered companies to find the cream of the crop can be a winning strategy. But you have to be willing to make a stand on which companies you think will be best. This fund, on the other hand, takes a scattershot approach, owning 150 different companies. So even though the fund has found some great performers like specialty retailer and equipment maker Nacco Industries (NYSE: NC) and liquefied natural gas specialist Cheniere Energy (NYSE: CQP), its results have been watered down by worse performers. As a result, the fund has never beaten the broad market. With less than $5 million in assets, the fund's days seem numbered.

4. StockCar Stocks Index Fund (SCARX)
Peter Lynch said to buy what you know. If you're a diehard NASCAR fan, do you really need any better reason to buy a stock than the fact that its name is on your favorite driver's car?

That's the investment philosophy behind the StockCar Stocks fund, which invests in companies that have some connection to NASCAR. So in addition to typical car-related companies like Ford Motor (NYSE: F) and Genuine Parts, you'll also find car sponsors as well, including PepsiCo (NYSE: PEP) and Home Depot.

The fund has actually done reasonably well. But with just $2 million in assets, it's clear that investors aren't buying the dubious value of the fund's stock-selection criteria.

Have fun
There's nothing wrong with having fun with your investments, but don't buy wacky investments just for their wackiness factor. Remember, it's your hard-earned money you're investing. Make sure you do right by it!

Tired of wacky investments? Jordan DiPietro has five stocks that can make ordinary folks rich.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.