First, look at hot business trends. The most often talked about trend is the baby boomer market, although there are others. Right now, health related products are hot within this demographical group and there are several ways to cash in. Private home care is one of these industries that is in demand right now. Health and beauty aids is another niche that is a great idea for a business. Medical transcription is yet another field that is in demand.
Another direction to look in is developing a personal business skill you have that is marketable. Writing (and I mean technical, freelance, fiction, subject matter expertise or otherwise) is in demand in a big way. There are tons of sites out there that will reward you for developing your flair at writing. Love to work outdoors? Landscaping and outdoor designing is very much in vogue. You can be a consultant, make your own products or make a living as a professional in a field you love.
Spend a lot of time online? Online small business niches are growing at an astounding rate. Online advertising is big business and you can find several niches to get your feet wet and it doesn't cost much for a start up. Affiliate marketing is an old favorite. Low end retailing is back in popularity and you can find lots of products and companies willing to cut you in on the action. Marketing a part of a real world business online is another great idea.
Still left searching for ideas? You can do some research to find a small business idea you can make your own. Netwwork marketing businesses are very popular if you are educated on what you want to get into and work with someone that can give you proper guidance on growing your business. Green businesses are another trend that is getting to be very popular. You can get into solar, making homes more energy efficient, recycling, or any number of business that make use of the new "green is better" technology wave. Whatever you do, get up and start searching for your gold mine right now.