Daifly said
That said, we use e-allocator - very user-friendly. They only thing it lacks is a forum as far as I'm concerned. The notice board is OK, but things drop off the bottom very quickly and it's not the easiest thing to read. A forum where you could post information would be a bonus so you could have bits on airfield ideas, aircraft tips etc.
www.aircraftbooking.co.uk has all these things and more besides.
Cusco