How do I set up my own Top-Level Domain (TLD)?

Replace your named.ca with a db.root file listing all TLDs (available from AlterNIC)
Edit db.root -- take AlterNIC's bogus TLDs out and put your bogus TLDs in.
Set up your TLDs like any other DNS domains.
Get other people to do the same thing -- offer to recognize their bogus TLDs if they recognize yours.
Spread DNS anarchy. Confuse corporations and governments. Keep people who don't know DNS from mailing you or seeing your web site -- get less mail from morons.
Form a Usenet-like non-organization to exchange bogus TLD information. Have flame wars.
(Alternate answer from Rick Moen: invade a country to take over its 2-letter ISO country code.)

so when people ask you how many languages you speak, do you tell them you also speak geekledegook?