Some, by the nature of their industry, aren’t allowed in the sport. Remember the whole brouhaha with AT&T and Sprint Nextel? AT&T is currently a sponsor (and in the Fortune 100) but its shelf life is limited. Conoco Phillips and other gas companies are precluded from NASCAR’s exclusive agreement with Sunoco.

But there’s several others that seem like they would be naturals for NASCAR sponsorship, but aren’t. From the very top of the list (Fortune 100 ranking in parentheses):

• Wal-Mart (1): A quick Google search comes up with one story about a short-lived promotion by Wal-Mart leading into the 2003 Daytona 500. But the mega-retailer has largely sat out any major sponsorships; but then again, it’s a company that doesn’t do much advertising anywhere. TV ads are seen here and there, but newspaper inserts were non-existent for many years. They’re at the top of the list, so maybe they don’t have to do a lot of marketing.

• IBM (9), Hewlett-Packard (11) and Dell (31): This would seem a natural fit. I interviewed Todd Brewer this morning; he’s the car chief for the No. 96 Cup car with J.J. Yeley and originally from Manassas; the full story — and it will be an interesting one — will run in Sunday’s paper and on our Web site. At any rate, he mentioned that he had a laptop that made his job so much easier; he said he couldn’t imagine going back to taking all of his notes with pen and paper.

With computers being as important as they are to racing — and, really, ubiquitous in our lives generally — it’s interesting that none have taken a leap to market themselves with NASCAR. IBM would probably be less of a player in that instance since dropping out the personal PC market a few years ago.

To be honest, when I started this, I thought there would be more. But some outfits, like Warren Buffet’s Berkshire Hathaway, have a wealth of companies under their umbrella; other places, like Goldman Sachs, don’t need to market their product to the general public. They’re merely interested in a certain segment of the market, which NASCAR may or may not reach.

• I’M GOING TO HAVE TO cut this short. The day just got a lot busier and I have a bunch of other things to attend to at the moment.

Please accept my apologies. We’ll have plenty of time tomorrow, when we’ll be live from Richmond.

(Photo by Mike Wintroath/Associated Press in Maumelle, Ark.)