The best thing you could do is to find a teacher who's got technique that you'd like to achieve. Failing the availability or scheduling possibilities of a teacher, the next thing I'd do is slow your playing way down. Look at your motion to see if you've got any excess junk in it. Work on getting your technique clean and proper at slow speeds and just build it up.

If you're not using fingers extensively at higher levels, you'll definitely need to. If you are but aren't getting anywhere, again, look at your technique for cleanliness. Beyond that, just gradually challenge yourself with faster tempos -- but ALWAYS PRACTICE THIS WITH A METRONOME. A good tool for this is to work through various subdivisions at increasing tempos. This will help your sense of time and keep you honest. I'd say pick up Master Studies by Morello, but build up from quarter notes to divisions of 10 or 12 off the quarter note.

As far as DVDs, again -- best thing to go for is a teacher, but the best videos for hand technique are:
JoJo Mayer - Secret Weapons for the Modern Drummer -- probably the most in-depth analysis of hand technique and solidly inspirational. I haven't digested it fully but it's very interesting and informative.
Joe Morello + Danny Gottlieb - (I forget the name, it's a three-dvd set) -- a good in-depth view of the Gladstone technique that Joe and Danny use. Due to the amount of material here it can drag sometimes, but Danny helps clarify things with the thought process of a student, so it's more informative and thorough than Joe's own videos (which are worthwhile as well).

Just keep challenging yourself. Practice with a metronome.

It's all about bringing things up to speed  slllllowwwllllllly.

Practice a rudiment - with a metronome - at a slow speed where it's super easy to
keep it clean and in time.  Inch up the metronome slowly.  Coupla ticks.  Keep going.

If you just try to instantly play something fast, you will probably - never get there.  If you take it in very small steps while practicing, you Will see some speed eventually come.

Beyond that, your grip and overall technique will be very important, and the best path to that is - some coaching from a good teacher/player.

In addition to following the advice of everybody above, you might want to record some video of yourself, if you haven't already. 

You might just think you're slower because, over time, your personal standards in regards to drumming have likely gone way up.  At least this was the case with me.  I thought I hadn't got any faster in years until I watched some footage of myself and saw that, while not the fastest, I had certainly gotten a lot faster, and not realized it.

I was recording some stuff this afternoon of just my playing on a snare drum. I wanted to hear some more after making the initial recording and so put it on and just ran through some of my general practice routines and was actually kind of surprised by what I heard.

The last time I recorded myself was about three weeks ago, and all I've been working on is VERY BASIC hand technique, ala Morello/Gottlieb, focusing on the freestroke/gladstone/whatever you want to call it method. My practice routine has been:
2-50 warmup at about 70 BPM using full strokes.
5 minutes of the following exercise at varying tempos (starting at about 80, then working on raising the ceiling higher):
8 eighth notes full stroke, rest two beats, 8 eighth notes half stroke, two bar rest, repeat

Then the four-bar-vamp method of stick control:
Each exercise through twice, then four bars of whatever hand you ended on, then the next exercise.
e.g.:
RLRR LRLL RLRR LRLL RLRR LRLL RLRR LRLL
LLLL LLLL LLLL LLLL LLLL LLLL LLLL LLLL
RLLR LRRL RLLR LRRL RLLR LRRL RLLR LRRL (etc)

Go through all three pages without stopping and without a break (you can do the page turn while one hand is doing the repeated strokes.) It seems to result in a lot more of your left hand doing the repeated notes which is good for us righties - you could probably just say, repeat with the opposite hand for lefties.

This is leading up to doing the continuous vamp, but I'm not quite there yet.

I've noticed a marked improvement in control, evenness, and accuracy in tempo. And this is not a whole lot of time invested. (And yes, I've noticed a bump in my higher speeds, without sounding like the whole thing is going to fall apart.)

It's not as glamorous as practicing 17:4 polyrhythms with a left foot clave while the right foot solos freely, but it's getting my sorry hands into less sorry shape. And surprisingly quicker than I'd expected.

Definitely. What's nice about that exercise, I'm noticing, is it's not done strictly in isolation, so you have to stay aware of what's going on and keep focused. Since you're plowing through Stick Control, it's not just a rote exercise like RRLL, RLRL or RLRR LRLL that are easy to execute without the focus and attention that you should have.

I tried the continuous vamp last night and that's one for some serious attention and coordination.