Do you use an email signature? Your know, that automatically attached list of info at the bottom of your sent emails. Name, phone number, job title, etc, etc. These are usually very formal no? While true of emails, over the last little while we have seen a new incarnation of the email signature, the mobile phone email signature.
Check out this graph from Bobulate. Sent from my Blackberry. Sent from my Verizon Wireless Blackberry. These are the regular ones we have grown accustomed to. But what about 'tapped with one finger on an iPhone. Please forgive any typos' or 'Apologies for brevity and any blunders in spelling; this was sent from my iPhone.' Definitely don't see that coming from PC email. What does your sig say?