I working on a system that will be doing spatial calculation across UK - finding users within proximity to some location. What I am after is data that would be a snapshot at certain point in time of mobile device positions across UK (to fine tune spatial grid index in SQL Server). If it's not a snapshot and has data on how people move it's even better, as I will be able to do concentration of people during time of day.
Update: If you have partial data of, lets say one region, of UK that would suffice too.
