GMAIL
Types these commands in the search box and click the "Search Mail"
View all unread emails type
"is:unread" without the quotes in the search mail box
View all read emails type
"is:read" without the quotes in the search mail box
View all starred emails type
"is:starred" without the quotes in the search mail box
Here are a few rich text options while chatting on Gmail through browser chat. Some options may or may not work in Gtalk
For strikethrough - Any word surrounded by hyphen is displayed striked - -Word- shows as Word