Phone/button configuration in Asterisk

How much phone configuration is actually done in Asterisk?
Is it possible to configure buttons etc centrally in a (relatively) nice interface (as is the case in a 3com/cisco/nortel system) or is it a case of using the web interface of each phone?

Given there are a heap of phone vendors, I am thinking the latter.

If it is via the web interface of each phone, how do people go with this in larger environments?

Thanks.