Register Your Email Address
your email address if they come looking for it...
All the following services allow you to proactively register your email address with them. Most will ask for a few personal details as well, to help others identify you if they search for you.
To get you started, here's the signup form for Reunion.com, one of the most popular resources for finding email addresses.
A number of large email directories also take submissions from members of the public. Links to each one are provided below.
Finally, many email change of address services also encourage people to submit new records.