There are a few organizations and businesses which deal in the domain industry who may be of interest to you if you are intending to get involved in domain drops. They are:

Nominet.

Telephone: +44(0)1865 332211
Fax: +44 (0)1865 332299

Minerva House
Edmund Halley Road
Oxford Science Park
Oxford
OX4 4DQ
United Kingdom

Sedo.

Sedo GmbH
Im Mediapark 6
50670 Köln
Germany
Email: info@sedo.co.uk
Telephone: (+49) 221 / 340 30 - 230
Fax: (+49) 221 / 340 30 – 102