I’m a big fan of Gmail. I’m a big fan of iPhoto. However, if I want to email my pictures from iPhoto with Gmail, I have to drag them from iPhoto to my desktop and then go to Gmail and browse for the file and then send it.
All of that isn’t necessary anymore with the help of a little plugin called iPhoto2Gmail, which allows you to, well, send pictures from iPhoto to Gmail believe it or not. It works through iPhoto’s File–>Export function and lets you login to your Gmail account and attach the selected photos to an email you can write in that same window (see screenshot).
If you use iPhoto and Gmail, I highly recommend this plugin. Its donationware, so if you like the work, be sure and donate (there’s a Paypal link on the site)!