before i send an email, i want a button next to spell check that saysemotion check, when i click it google grabs the words and phrases (+ some historical sets) and computes:
1. the negative/positive tone of the email relative to other emails i send (0-1 scale)
2. the relative negative/positive tone of the email to all emails sent by all people (0-1 scale)
3. the negative/positive tone of the email relative to emails i send to that person (or that person receives)
4. most impt: the expected response rate and time to respond.
5. the expected negative/positive tone of the response.
i bet you could pull this stuff out using: words and phrases in the email, the recipient, gender?, ethnicity?, historical emails sent and responses, etc.
cap it with a suggest function (a la spell check), that tells you to add a smiley face here or there, or switch words/phrases.
eventually, get to a health meter next to all of my contacts showing the imputed positive/negative stance of our relationship based on message flow, i like it. time for gmail labs to get crackin'.