Gmail’s getting more like a desktop email client every day. The Gmail team recently added the ability to drag and drop files into emails to add them as attachments, and today they announced that you can now drag and drop images onto a message to insert them inline. This functionality is currently only supported in Chrome, but is apparently coming to other browsers “soon.”
Note: I can’t get this to work in my personal Gmail account yet (using Chrome 5 on my Mac) — it keeps wanting to open the image in the browser window, rather than inserting it into the email. It is working perfectly in my Google Apps Gmail account, though, so maybe it isn’t rolled out to all accounts just yet.
Let us know whether this is working for you in the comments.