Turn off chat in Gmail
Its seems simple enough but it took me a little while to figure this out. I was getting annoyed at constantly being "annoyed" with people trying to instant message me whenever I tried to check email. Just scroll down to the chat area on the left side you can either click on the drop down arrow to the right of your status message and select turn off chat
...or you can click on options just below the chat area and select turn off chat...
See that wasn't hard....now you can check email without being bothered....I use Pidgin anyway