From Weird Solutions:
Version 2.1 offers complete control over address allocation in any network. A new user interface makes configuration easier and quicker, but the real power boost is the new Logical Expression Parser. This gives you absolute control over your network. For example, you need all clients with 3Com network cards to be in Scope A on Mondays and Fridays but in Scope B on all other days. Easy. You have a remote subnet with a DHCP server of it's own. You want those clients to only get an address from your DHCP server if they can not get one from the remote server after 10 seconds. DHCP Turbo does all this with ease.