The product is pretty sweet.  I really like it.  It helps me push myself faster and farther, by breaking the monontony of swishing water.  I'd suggest wearing earplugs with it to fully rid yourself of water sloshing sounds.  Another great thing is that you can attatch it to any googles you choose, even Swedes.  The one drawback is that when you move your goggles to your forhead between sets the pads lose contact with your face and blare really loud music everywhere.  
Even so, I love them and would suggest that everybody everywhere buy them.

I'm not one that normally writes reviews, but this product is truly amazing.  I was skeptical until trying it for the first time.  Just having music alone has doubled my work-outs.  I did have to put the MP3 player on my TYR goggles, tighten the strap a little more, but all is well.  The goggles it comes with didn't fit my face.  I've been telling all my swimming buddies at 24 hour fitness and after they all tried it, they were amazed as well.  Also, I saw that there is a review saying the software only works with Windows 98.  That's untrue.  I'm running XP and am having no problems.  In fact the way it works is, it just loads as another drive on your machine, so all you have to do is drag .MP3 to it.  SUPER EASY.

Also, as mentioned in other reviews.  The sound is much better in the water with no loss of sound when taking a breath.

I'm on my second player and this one just gave up too. My first one had one side go out. If I moved the wires around I could get it to work. It was repaced at no cost. One side went out on my second one after a few months. I lived with it until the other side went out. I've written to customer service, but they aren't getting back to me promply. It's a great product to own. I bought my first one when they were over $200. I don't know if I'll buy another if they don't replace this one. I think I'll wait for the next design and hope for better quality.

The right side went out after just a few months.  It's not worth using with only one side working.  I read a review from another user who had the same experience TWICE.  HE mentioned that both sides went out on his second unit.  I really liked it while it worked, and today it just wasn't as enjoyable swimming without it.  Although, I'm really reluctant to invest in another unit until Finis can convince me that they have improved the reliablity of this product.

Based on other reviews, the audio out of water was better than I expected, but it truly shines when it becomes submerged.  Once the unit and pads are in position it is very comfortable to wear and easy to control.  This is the only waterproof mp3 player I've tried so I can't compare, but I'm very happy with it as a tool to escape distraction and boredom while swimming.

Regarding other review comments that it only works with Win98, I am using it successfully with WinXP.  I did have to reset the unit when I plugged it in (button over on/off button) and it immediately connected as a Removeable Memory device and I was able to drag-and-drop songs onto it.  The accompanying CD driver is only for Win98, more recent versions of Windows don't need a driver.

Antoinette may be using the SwiMP3 iproperly, as explained in the instructions.

Excellent product. Swimming produces hurdles to audio, which impact the sound quality.

The sound is very low while out of water. Under water, the sound rises and is quite clear. Out of the water, the sound again drops, making this less suited to the certain strokes.

It's not for audiophiles. The sounds of swimming hinder the ability to provide outstanding audio. However, the sound is much better than I expected.

The setbacks are the cost and the small memory size. The unit is expensive, due to the limited market. 128 Mb is very limited for an MP3 player. At 64Kbps, I was able to get 49 songs on my SwiMP3, a little over 2 hours of music. That bit rate is of low quality. Encoding the songs to 96 Kbps, the capacity drops to about 34 songs. This results in a lot of trips to the computer.

Considering the limitations of an underwater MP3 player, the SwiMP3 rises to the challenges quite well.