If you have configured your router as a DHCP client, you can use the default router option received in a DHCP reply as the next-hop for a static route. For example:
ip route 10.0.0.0 255.0.0.0 dhcpYou could use this functionality in scenarios where your core network uses DHCP (for example, in metropolitan networks using layer-2 Ethernet transport from an ISP), but your router needs a different default route.
You can also use this feature to change the administrative distance of the DHCP-based default route (or you could use the ip dhcp-client default-router distance value configuration command that one of the readers described in a comment to a previous DHCP-related post).
Any other good ideas where this might come handy? Post them as comments ...