looking for a travel agent where I could buy a round trip ticket US/Australia/UK/US leave10/07-02/?

Leave US Sep 07 to Aus leave
aus Aug 08 to UK Leave UK Feb 09 to the US

Consider joining SERVAS, which is an international network of travelers and hosts who have passed a background check: www.servas.org

Before you buy an airline ticket, look at the Around the World fares offered through the three major airline alliances:

http://www.oneworld.com/ow/air-travel-options/round-the-world-fares

http://www.skyteam.com/EN/benefits/aroundTheWorld/index.jsp

http://www.staralliance.com/en/travellers/fare_products/round_the_world_fare.html