Cross referencing in the verb

One of the most delightful things to me about the Sumerian verb is the
cross-referencing of case relationships it takes upon itself.  For
those unfamiliar with the mysterious Sumerian verb, the existence of a
locative, say, in a sentence will trigger an infix in the verb affix
chain.

I think this is cute.  Sumerian was the first time I'd ever run across
something like that.  We're all used to incorporating subjects,
tense/aspect, formality, and not a few languages tack on direct and
indirect object pronouns.  This locative marking was quite a surprise
to me.

I'm curious to know what other sorts of things languages have decided
to encode in the verb, apart from the ones I've just mentioned
already, in either real or constructed language.  I covet a list of
many possibilites for the next time I decide to create a vast verbal
monument. :)

--
William Annis                http://www.aoidoi.org/
annis@aoidoi.org             Classical Greek Poetry