As part of an archaeological project aimed at developing a 'standard' approach to low-altitude UAV surveying I spent a lovely and very productive couple of hours at Stoney Littleton Long Barrow near Bath. The site is amazing and is one of the finest accessible examples of a Neolithic chambered tombs in the UK, with multiple burial chambers which are open to view.
The actual survey was done with a DIY hexacopter, based around an APM 2.6. I used a Canon point-and-shoot running CHDK and an intervalometer script. The actual survey was done in under an hour.
A resulting 3D photogrametry model, created using Autodesk's free to use 123D Catch can be viewed here.
The main goal was not perfection but coming up with a procedure that most people can follow and which gives pretty good results.
If you'd like to get involved we're inviting feedback on our good practice guide.