by James Gaskin -- Just as you can specify a Web site for Google searches ("google tips" site:itworld.com), you can use a variety of search operators with Gmail. Two caveats: Gmail searches won't suggest spelling for you or handle plurals ("dog" won't return "dogs").
Common e-mail header information (to, cc, bcc, subject, and from) can be added to search queries. Examples include "to:John" or "to:email@example.com", "bcc:Boss", "subject:netbooks". Add the "in:anywhere" query and include the Trash and Spam listings in your search (they're ignored in regular searches).
Gather all messages with attachments by searching "has:attachment". Narrow that list by searching for "filename:doc" or "filename:pdf" to return just those types of attachments. All file extensions work.
Searching by time requires you to put the date in the form yyyy/mm/dd. Search after the Ides of March using "after:2009/03/15" and you'll get all messages after, but not on, March 15th. Search for earlier messages using "before:2009/03/15" and you'll get all message before, but not on, that date.
Labels in Gmail take some people by surprise, and a few have trouble making the switch from nested folders to labels. Just remember a message can only be in one folder, but it can have multiple labels.
Search using the labels by adding "label:inbox" or "label:sales" in the query, depending on your predefined labels. System labels such as starred, drafts, spam, trash, read, and unread work too.
Boolean operators AND, OR, and NOT can be used, as can parentheses and braces for grouping search terms. Searching "from:jane subject:(zoo|tigers)" will return messages from Jane about the zoo or tigers.
Yes, most of these tips work in Calendar, Docs, and other Google Apps.
This tip comes from Scott Granneman, author of Google Apps Deciphered. Prentice Hall.