Whether it's from home, work, or signatures on forums. Here's an example of mine from work. Sorry, not giving out my actual phone numbers.
AD1(AW) James H. Vanderbeck II
AIMD 040 (QA) 400 DIV QAR
DSN: XXX-XXXX
COMM: XXX-XXX-XXXX
“MICROSOFT: Where do you want to go today? APPLE: Where do you want to go tomorrow? LINUX: Are you coming or what?”