Plugin for Sublime Text 2

signature.py

# Tools > New Plugin
# Save as signature.py

import datetime, getpass
import sublime, sublime_plugin

class SignatureCommand(sublime_plugin.TextCommand):
    def run(self, edit):

        signature = "[%s %s <%s@agilionapps.com>]\n\n\t" % (datetime.datetime.now().strftime("%Y-%m-%d %H:%M"), getpass.getuser(), getpass.getuser().lower())

        self.view.insert(edit, 0, signature)


# In Preferences > Key Bindings - Default 
# Add a new entry
{"keys": ["ctrl+alt+s"], "command": "signature" },