On the rare occasion when I have been asked to produce a 2nd photo ID (one of the more pointless and idiotic security procedures), I've been told that a company ID, credit card w/photo, etc. is acceptable. (It would be unusual for anyone other than a passport holder or government employee to have two gov't issued photo ID'S.
There's nothing to prevent you from having your own sole proprietorship called "John Smith Ventures," for example. The sole function of this business (which doesn't need to be registered or incorporated) would be to "look for business opportunities." Unless it has revenues and expenses, there wouldn't be any need to report it on your tax return.
Of course, it would be important for you to have a company ID for security purposes, so you'd need to spend 20 minutes printing one up on your color laser printer, sticking your photo on it, and getting it laminated down at your local copy shop-- all-in cost not more than a couple of bucks.
Although most people I travel with don't carry more than one form of photo ID when travelling domestically (for security purposes, it's actually better not to carry your passport for domestic journeys-- too much risk of loss), I suspect it is common practice amongst sophisticated terroists, con artists, and miscellaneous other self-respecting felons to carry 2 forms of photo ID to deflect suspicion.
[This message has been edited by HKG_Flyer1 (edited 02-10-2002).]