Electronic "post it" campaign for Twitter/email

Information for the business: We are a communications agency
Design details: We would like to send out over a period of weeks some "post it" style electronic notes for Twitter/Linkedin. We have a number of messages that would need to be illustrated in a new house style for this purpose. When the recipient sees/receives the post it/message we would like it to have a relaxed fun feel to it. The post it note to follow our colours so maybe a blue back ground with chalk style writing in white and orange. White for some messages and maybe orange for messages with a different style. Sustained engagement is very important to us so we want the recipient to look forward to seeing our message.
Target audience: Event managers/Board Directors/
Ideas for the visual style: Blue background with white writing to look like a post it or something similar.
Where the design will be used: Web/Phone
Extra notes: www.deeperblueltd.com