Just reread Jonathan's post properly - so there aren't vegan cake audax controls after all
Sod it, thought things had improved!
Seriously though one of the things that encouraged me to make the transition from veggie to vegan a couple of years ago was the memory of a young, relatively inexperienced, vegan, audax rider called Juliet who would mostly sustain herself via a saddlebag of home-made flapjack. She failed to complete the tough Brian Chapman 600km (that's Chepstow - Anglsey - Chepstow, there are hills) in her first year of riding but was back the following year to complete successfully. So any excuse I, as a much more experienced AUK, had of needing dairy to sustain me through long rides fell to dust!
The above mentioned Dave Poutney has organised for many years two classic, tough, but beautiful rides not far from the Welsh borders, the Elenith 300 and the Kidderminster Killer 200.
I'm not sure a 24hr ride on it's own is accepted as a PBP qualifier anymore, I think you have to do a Super Randonneur series of a 200, 300, 400 and 600km earlier the same season. Looks like there may be a shortage of places next year and BRM audaxes completed this season will give priority. Qualifying for PBP 2010
I wrote an 'Intro to Audax' for the Vegetarian Cycling and Athletics Club
newsletter earlier in the year in an attempt to temp new riders. There's a copy on my new blog here