Yes a contact list is a very good idea or even just all swap numbers at the start of the meet (Can bluetooth do a mass transfer)
The bucket idea is a good one and it has come up before but do be aware that you may need certain permisions to collect and I thik you will find that you will not be alowed to collect most of the main venues that we visit due to them being owned by private companys and there are many restrictions on collecting such as licenses
Children in need is a strange one and aroung that time you are alowed to go out with buckets almost anywhere but only at that time of year
This may sound a but draconian but there were alot of people going round london colecting for charitys and keeping the money (crafty hey)
So they "legislated" it to keep an eye on things
But if some people are willing to do the ground work and set it up I see no reason why not but don't just roll up with a bucket and start collecting as you can be detained by the police if you don't have the right paperwork (they will think your a fraudster )
Jason
