Giles,
A buyer's agent will work on your behalf in finding properties, negotiations, showing you properties and point out things you might not see/know to look for, etc. Going without an agent is risky, as the seller's agent is working on behalf of THEIR client and not on your behalf. They still have to ethically do business, but they are really trying to get every penny out of you for their client as they can.
Keep in mind that you don't have to pay a penny to use an agent to help you buy a property. Typically the seller agrees to pay 6% commission to sell the house, and if the buyer has an agent the buyer's agent and the seller's agent will split the 6%. So the SELLER is paying your agent to work for you.
Also, a buyer's agent has MLS access and can set up an automatic search to send you emails with properties that fit your criteria. The system does the searches for you, you just look through properties based on what you want, and you let the agent know if there is anything you would like to go see in person.
And if you don't end up buying anything, you owe the buyer's agent anything. Granted, they may not be too happy if they drove you around to 50 different houses and you didn't buy anything, and they might be a little more hesitant to help you if you come back a few months later and tell them you do want to buy something now.
If you are new to the home buying experience I would definitely recommend using someone. They can help educate you as well as be your advocate in negotiations and the closing process.
Hope that helps some.