You can contact me at my @gmail.com email account, with the username "jjberthels".
Email is preferred, but you can also IM me on google talk with the same address.
I can also often be reached on public jabber as "jbert" on the "jabber.org" server, and slightly less often on MSN with the address "john.berthels" and the domain "hotmail.co.uk".
For business enquiries, please feel free to IM me even if I am marked busy.