Like Cindy, I rarely will even show property without the buyers brokerage agreement signed. The agreement doesn't deminish the buyer Realtor's efforts to find their client the home they want. They don't get paid unless they buy a home. Even if the client does find the home by visiting an open house, happen to drive by, etc ... the buyers Realtor is still there for the negoiation, offer, inspections and follow thru until escrow closes. Finding the house is usually the easy part.
What is the difference between a seller signing a listing agreement exclusively with an agent and a buyer doing the same on the buy side? Does a seller feel less "tied down?" In either case the Realtor can be fired for non-performance.
Interview agents until you find one the fits with you and your needs and wants. Make sure you lay out your expectations of the Realtor. That way you both will be on the same page.
Cheryl is right - interview several Realtors (not just a real estate agent) and find one that you are most comfortable working with to represent you. Don't be afraid of signing a buyer-broker agreement. Service does NOT stop with your signature. The Realtor does not get paid unless you buy a home.
If you don't use a buyers agent and you buy a home, I assume you plan on using the sellers agent to represent you? Why? The seller pays the commission for your Realtor - who will represent you exclusively and negotiate all aspects of the transation with the sellers agent. Who do you think wins in a negotiation where one Realtor represents both the buyer and the seller?
The link below will provide information to you and your family on the advantages of using a buyers agent. Good luck. It's a great time to buy!