Learning Letters (at 18 Months)

It's safe to say that Bear has a total letter obsession. Anywhere we go, he spots a sign and immediately starts pointing and sounding out each letter. He knows the phonetics of every letter of the alphabet (though he gets them mixed up occasionally). Zach and I cracked up last week when, on a trip to the mall, all of Bear's cousins were playing in the playground. Bear, on the other hand, was pointing at the JCPenney sign saying "J! J! C! C! C!" We love our little alphabet boy!
I'm not at all ashamed to share our secret. We've been working on letters for awhile, mostly through books and magnet letters on our fridge. Bear loves to play with and move around the magnets.
We hit the teaching jackpot, though, when we bought this DVD off Amazon for just $7.50.
He only watches it in the car, several times a week, and gets so excited every time we turn it on. He still doesn't say the actual letter name, just their sounds, but we're hoping that will come soon. We're continuing to do lots of reading and afternoons spent with sidewalk chalk. Bear loves when we write the alphabet on the driveway! #littlenerd

Next up is numbers; do you have any teaching tips? Leap Frog also makes a number DVD that we're planning on ordering soon, and hopefully it will be equally as effective.
Cheers to the almost-weekend!