The possibility of customizing the signature, allowing users to directly insert images, in addition to changing the color, size and type of font, is one of the most requested features in the Gmail Forum. I believe that you will only lose out on the possibility of requesting confirmation of the reading of sent messages.
In mid-April, I published, here on Google Discovery, a video lesson where I teach, in addition to inserting images in the body of messages, how Gmail users could use the feature Canned responses, available on Labs, for creating signatures using HTML formatting.
The option was actually an alternative way of getting around this deficiency from Gmail.
But, to everyone’s delight, Google has just announced the implementation of the possibility to edit subscriptions through an editor rich text.
To personalize the subscription, the user must access settings and find the option signature. The editor rich text of signatures is the same used by Gmail when editing webmail messages. In it, it is possible, in addition to modifying the font color, size and style, the user can insert bookmarks, links and images, among other options. After customizing your subscription, just click Save settings.
The only difference, in relation to the making of a message, is in relation to the insertion of images. In the case of the subscription, it is only possible to insert an image via link. You cannot upload an image from the user’s computer.
When the user is going to edit a new message, the signature defined by him will be displayed automatically. Even so, if you want, the user can make any kind of changes to it. Remembering, of course, that such a change will not be saved in your settings. It will only apply to the current message.
For users who, like me, have several accounts set up in Gmail (a new post will soon be the theme), there is also the possibility to customize the subscriptions for all extra accounts.
If you also have any suggestions for Gmail, use the special page Suggest a resource for Gmail.
UPDATE:
Initially available only for Gmail, Google has just released the novelty, too, for users of Google Apps.