Equipment Usage...How much is too much?

When it comes to using equipment in practice, I have to believe that I probably use equipment more then most...and I often feel as if I toe the line between keeping my swimmers ages 10-16 interested and engaged while at the same time keeping the workouts on schedule and flowing.  I found that by using equipment at key points of the re-construction of a stroke/turn helps to re-enforce the muscle memory of what you are trying to emphasize.

First, the equipment the kids in our group have.  We use the following:
Kickboard
Long fins
TYR Catalyst paddles (size appropriate for each kid)
Snorkel

Here is some equipment I have that we use:
5" PVC pipe
Tempo trainers
Mini-buoys
"Swim bones"

I have a short list of my favorite drills where I incorporate equipment in order to get the concept introduced, understood, and the correct parts of the concept emphasized with the type of care and attention to detail I typically like.

Backstroke
Drill:  Triple Scoop
Equipment Used:  One TYR Catalyst Paddle
Description:  The swimmer lays on his/her back grabbing the bottom of the paddle and allowing the rest of the paddle to press against the forearm.  With the swimmer on their side, the only movements in this drill aside from a steady kick is that the hand grabbing the paddle will complete a 3-part stroke cycle while the other "free hand" stays glued to the side.  They then pull three times.
1.  Small movement anchoring the hand down, then with an underwater recovery and the palm of their hand facing upward, sliding the hand back behind the swimmer's head.
2.  Downward movement, focusing on a high elbow catch throughout the pull stopping well before the hands get to the hips , then with an underwater recovery, sliding the hand back behind the swimmer's head.
3.  A full backstroke "pull" that finishes with the hands snapping past the hips.
***Special Note:  Because there is no above water recovery, this drill does a great job isolating the pull.  Depending on how good your swimmers are at catching water, you may use buoys and ankle bands for those a bit more advanced.***

Flip Turns
Drill:  PVC Kick Flips
Equipment Used:  5" PVC Pipe
Description:  I know I am going to make this sound way more complicated then it really is but here goes.  I typically will make the kids do something like a 400-500 single arm freestyle (R/L by 25) with the off arm holding the PVC pipe at their sides.  When they get to the flags, both hands lock onto the PVC pipe with their hands at the waist.  They kick in towards the wall with their eyes looking straight down.  They have to "FEEL" the wall approaching and activate their turn while still keeping their eyes looking down and their hands still locked on the PVC pipe, which makes the turn a little bit harder because it is done using primarily the core.  The PVC pipe re-enforces the streamline as well as helps with the posture needed to complete the turn as if they were sitting in a chair.  This has been a HUGE help in tightening up what we are doing in and out of our walls.

Butterfly
Drill:  Varying Kick Drills
Equipment Used:  Snorkel
Description:  I typically like to vary the placement of the hands throughout the kick.  An example set would be something like:

24x25 :40
8x
1-dolphin kick, hands crossed on chest
2-dolphin kick, hands out in front of shoulders
3-dolphin kick, hands at sides

I personally love the head and body position that using a snorkel emphasizes within butterfly, promoting proper body alignment while simultaneously keeping the stroke a bit flatter, allowing undulation without allowing (without choking because they buried their snorkels underwater) over-undulation.  Is that a word?  No sure, but I'm rolling with it.

So, I have given you a few different things I like to do.  What are your equipment-aided drills that you do?  Inquiring minds like to know.