Answer by Paul Ward

This will get you half way there:

Use MyDatabase
Go

select b.name, a.last_execution_time
from sys.dm_exec_procedure_stats a 
inner join sys.objects b on a.object_id = b.object_id 
where DB_NAME(a.database_ID) = 'MyDatabase'

It will tell you the last time a stored proc was executed.

As for who ran it, as far as I know that is not recorded. You could use profiler to recored this, but i wouldn't do that on production server.