My favorite...
SELECT objParent.name AS parent, obj.name, col.*
FROM sysobjects obj
LEFT JOIN syscolumns col
ON obj.id = col.id
LEFT JOIN sysobjects objParent
ON objParent.id = obj.parent_obj
WHERE col.name LIKE '%Comment%'
OR obj.name LIKE '%Comment%'
Above I'm searching for "Comment".
Drop the percent signs if you want a direct match.
This searches tables, fields and things like primary key names, constraints, views, etc.
And when you want to search in StoredProcs after monkeying with the tables (and need to make the procs match), use the following...
SELECT name
FROM sys.procedures
WHERE OBJECT_DEFINITION(OBJECT_ID) LIKE '%Comment%'
Hope that helps, I find these two queries to be extremely useful.