Yes but the original poster mentioned a static IP, not DHCP..
The problem is most likely your DNS configuration. You may have set this with a graphical admin app but under the surface the contents of the /etc/resolv.conf point to the DNS server your computer will use to resolve names/numbers. The boot delay is various things starting up which want to access host names your local machine doesn't know and for which it has to refer to a DNS server. Unplugged yours isn't reachable and it has to "time out" on each attempt.
As someone else mentioned, RedHat/Fedora like to put your system name and localhost all as one entry in /etc/hosts, something like this:
127.0.0.1 mycomputername localhost.localdomain localhost
I like to keep only localhost on the loopback interface and the system name on it's real IP, something like this:
127.0.0.1 localhost.localdomain localhost
192.168.0.1 mycomputername mycomputername.mydomain.com
You might additionally have some success with configuring DNS server (bind) on your own machine there and pointing DNS queries to yourself. Whether the cable is plugged in or not, 127.0.0.1 will be available. On top of that, you can setup forwarders so that hosts your own box doesn't know how to resolve it forwards on to your companies DNS server, some info after a quick search:
Good luck, I'm one of 2 people at my place of employment now running FC4 desktop machines entirely and so far with great success.
PS. If your company has a DHCP server configured and you could use DHCP instead of a static IP that might resolve much of this. The DNS server entries in /etc/resolv.conf would dynamically be setup by DHCP upon each boot.