Tobit is a small consultancy specialising in network related work.
My work includes both wire and wireless networking, more information and some examples are located here
Tired of dealing with all those sendmail bugs and exploits? Can't be bothered learning all those arcane rewrite rules? Want a mailer that can handle a humungous mailing list efficiently? Use exim, it's simple to configure, quick and secure - what more could a sysadmin want?
Contact information for the company is available here
Here are some further miscellaneous links.
For the curious, the company name comes from the Book of Tobit in the Apocrypha