In today’s shaky and unpredictable economy, many decide to take their fate in their own hands and start their own business. In case you’re considering such a move, we’ve got the 10 best entrepreneur ideas out there listed, for your inspiration. They’re simple enough to be called works of genius, they come from all sorts of business fields and they made loads upon loads of money in 2010.

1. Foursquare

Foursquare is one of the best entrepreneur ideas out there simply because it capitalizes on the gigantic and ever-expanding trend of smartphones. It’s a location-based app, launched during the 2009 SxSW Conference in Austin, Texas, a famous hub for harvesting brilliant ideas. The concept is simple: “check in” at your favorite hang-out via smartphone, leave “tips” and earn badges. According to Dennis Crowley, the New York-based co-founder and CEO of Foursquare, “It’s about making the city playful and easier to navigate, and it incentivizes people to explore.”

2. BillShrink

BillShrink is one of the best entrepreneur ideas we’ve come across because it manages to make money of a very real situation, affecting so many people worldwide. It’s an online application that asks you about your bills and spending habits and then recommends deals, tailor-made for you to reduce your day-to-day costs. “The recession has been incredibly helpful to our business,” says CEO Peter Pham, whose website gets more than 250,000 unique monthly visitors.

3. Doggles

While your first reaction might be, “Seriously? Fashion sunglasses for dogs?!”, think twice before you sneer. Apparently, this truly deserves to be listed as one of the best entrepreneur ideas out there, since the business makes no less than $3 million a year. The company was basically germinated in 1996, when founder and dog lover extraordinaire Veronica DiLullo made the first pair for Midknight, her border collie-Lab mix. According to DiLullo, “People started to contact me to make pairs for their dogs for all sorts of reasons and that’s when I realized there was a glaring need for a product like this.”

4. FloH Club

This item on our list of best entrepreneur ideas is particularly geared towards seniors. It was developed by former Brady Bunch mom, senior actress Florence Henderson and it basically serves as a telephone-based tech-support service for seniors. Forget about endless calls from your grandma asking you how to set the timer on the microwave oven. With the advent of FloH Club, says Henderson, “I wanted to make sure there was no such thing as a silly question.”

5. Terracycle

Tom Skazy, the guy who founded and runs Terracycle, is basically making money from worm poop. That’s right. He picks up trash from major consumer goods packaging companies – specifically, stuff that can’t be recycled – and makes school supplies and gardening tools that go on to be sold at major retailers. He made no less than $20 million in sales in 2009 and all that money came from the very simple concept of making major companies feel more environmentally aware.

6. Booty Camp

Never mind the double-entendre name. This is one entrepreneur idea geared toward toddlers and their increasingly busy parents. Wendy Sweeney teaches rug rats how to use the toilet without help or reminders, all in a one-day, intense training session. She charges $300 to $500 per class and holds the sessions at her West Chicago home. This idea reminds one that all industries that have to do with children are as lucrative as ever, with child care, sports coaching and tutoring raking in an estimated $47.5 billion in 2010.

7. Rent a Coder

Who likes html and other programming code? Well, in earnest, absolutely no one – barely anyone gets it, yet we all depend on it these days, as the Internet is taking over our life. Except, of course, for programmers such as Ian Ippolitio, a Tampa, Florida-based coder/entrepreneur who launched a programmer outsourcing business in 2002. He later changed its name in and made $3 million in 2010. Not bad at all, huh?

8. Blik

Home décor is also a great line of business to make money. Since the recession is forcing us all to spend more time at home than before, we like to be surrounded by pleasant, customized living environments. That’s exactly what Scott Flora and Jerrine Neils realized when they decided to open Blik. The company produces and sells wall decals that reproduce famous works of art for $50 to $70. According to Flora, “Applying art directly to a wall has an innate connection with people. It goes all the way back to when you were a kid and you were drawing on the wall with crayons. That same excitement we had then somehow permeates everyone.”

9. Spoonful of Comfort

With such a lovely brand name, it’s no wonder Spoonful of Comfort is one of our best entrepreneur ideas on the list. Founded in Bradenton, Florida by Marti Wymer and open for business in August 2009, the company delivers fresh homemade-like food, right to your doorstep, for incredibly low prices. A 64-ounce jar of chicken noodle soup costs $32 and side dishes are $6. “It’s all about making someone feel better, so the pressure is getting it there on time,” Wymer says. “And I’m motivated to do things well because I want to build a legacy for my family.”

10. XRKade

Lenny Lowenstein opened XRKade in 2003 – actually, he took over an existing business and used the know-how he had accrued as vice president at 24 Hour Fitness. His strategy was as simple as it was effective – to offer his customers a serious workout while they essentially play arcade-style games. “We wanted to connect fitness and technology to create active play,” Lowenstein says. “I challenge any traditional club owner to look at their treadmills during prime time and find a smile.”