Most likely, his DVD player wouldn't have any digital connections unless it's practically brand new. The ones with DVI/HDMI have just started showing themselves in the past 6-8 months, and then they've been considerably more expensive than the regular analog models. However, it really depends on the quality of the machine. Even some of the DVI/HDMI versions have digital to analog connections inside the box (which is just STUPID in my opinion). You really need to do your homework if you buy a new DVD player to make sure that everything is digital to digital. Also, do NOT spend extra money on a DVD player that "upconverts" your DVDs to 720p or 1080i, that's one of the biggest marketing gimmicks I've ever seen. If anything, that could make your picture WORSE. You physically cannot add pixels to a movie and have it look as good as the original. Some DVD players suffer considerably in quality when you upconvert, some don't. I'd just say don't bother with an upconverted DVD player. If you want HD DVDs, wait until BluRay or HD-DVD comes out, then buy a DVD player with DVI/HDMI.
Also keep in mind that just because you're using DVI, that doesn't guarantee a full digital experience. There are three types of DVI. DVI-I, DVI-A, and DVI-D. DVI-D is full digital/digital quality all the way through, DVI-A adds an analog conversion to the mix and DVI-I works with both digital AND analog.
You're generally safe with HDMI though.
Most people probably won't be able to tell the difference between an analog and digital connection if you're using crappy cables or a poor quality HD monitor. CABLES MATTER!! I wish I had a dollar for every person who's asked me why their picture isn't as good as the one they see in the store, or as good as mine. The first question I ask is what kind of cables do you use? Most of the time they say "I don't know" or "just whatever was on the shelf and cheap". At that point, I tell 'em to take the junk back and get some decent cables. Again, this is where you need to do some homework. The old saying "you get what you pay for" applies to cables too.
HD is a very exciting technology, and it's not exactly a cheap thing to get into, but if you want the best TV/Movie experience possible, there's no alternative to HD (right now anyway). We're living in a very exciting time as far as TV goes. The old NTSC standard was created in the 1930s and color was added in 1941 if I remember correctly...not much has changed since then. If you find a color TV from 1942 that still works (no blown tubes, etc) you can still watch virtually anything that's broadcast over standard definition TV channels. Can you name one other technology that we're using today that is exactly the same as it was in 1941?? Didn't think so. It's TIME for an upgrade.