It has some use in regular expressions (beginning of a string, or "not" inside a character class), also in shell expansion (related to the regexp use) for example 'ls *[^z]' : list all files with name at least one character long, not ending in 'z'. Of course, you need the [ and ] mapped for that to be really useful!

BTW, I discovered that if you drop the dead_ from dead_grave and just put grave, you don't have to press it twice!