GMail Tips

While many of your might be aware of some of these Gmail tips - this blog post from Digital Inspiration by Amit Agarwal is a good repository for Gmail search tips.  The popular 'commands' are:

label [label name]
is [read/ unread]
has [attachement]
in [ chat| anywhere]
filename [name of file or extension/filetype]
from [name or domain (xyz.com)]
to [name or domain ( xyz.com)]
subject
after [date in yyyy/mm/dd format]
before [date in yyyy/mm/dd format]

You can get an FAQ style example list in the post.