I found this pretty sweet article about Fred Birchmores who cycled 40,000 kilometers for two years on a single speed fourty-two pound bicycle.
Two new records were set in December 2012:
The rules state “the journey should be continuous and in one direction (East to West or West to East), that the minimum distance ridden should be 18,000 miles, and that the total distance traveled by the bicycle and rider should exceed an Equator’s length, i.e. 24,900 miles.” They also state that: “Any considerable distance traveled opposite to the direction of the attempt must be discounted from any calculations of the overall distance traveled,” and that the route “must be ridden through two approximate antipodal points.”
The male record is currently held by Thomas Großerichter, who completed his attempt in December 2012 having covered the distance required by the Guinness rules in 105 days 1 hour and 44 minutes (including transit time concerning the new Guinness rules). Juliana Buhring holds the first female record, completing her attempt in December 2012, in a total of 152 days and 1 hour (still awaiting verification by the GWR).
http://en.wikipedia.org/wiki/Around_the_world_cycling_record