Each year for the past few years, a bunch of very dedicated and probably slightly insane members of the advertising and music video community have undergone an extraordinary challenge to raise money for the cancer charity Leuka. They are preparing to set off once more - and they need your support.

The Fireflies is an annual cycle ride, but no ordinary cycle ride: it involves riding more than 1,000 km over eight days in June, from Geneva to Cannes. This means cycling through the Alps, and the highest mountain passes in Europe, before the riders reach Cannes on June 18th, during the Cannes advertising festival.

The purpose is to raise money for Leuka, which is dedicated to raising money for the haematology unit at the Catherine Lewis Centre at the Hammersmith Hospital. The unit undertakes research into the causes and treatment of leukaemia - the model of all cancers. They believe that achieving a greater understanding of leukaemia will help in the fight of all forms of cancer.

The Fireflies motto is "For those who suffer we ride", and among those taking part in this year's Fireflies include (for the fifth time) slightly insane promo producer and BUG co-curator Phil Tidy - pictured here after an especially enjoyable leg of the journey last year.

You can find out more about Leuka here, find out more about Fireflies here, and sponsor Phil for the Firefies ride here.