"There are times that I really feel I'm in the 21st century", Emily said, "This is one of those times."

Very impressive. The speakers are a bit bigger than I expected; I think the SONY SRS-T77 is more compact. It's the only comparable product; but it's twice the price of the SRS-T55. Mind you, these are so good I'm tempted to keep them by my iBook and buy the SRS-T77 for the office.

The speakers folded up are 2x3.5x4 inches. The battery compartment, holding 4AA batteries, makes up a fair bit of the size -- to be significantly smaller the device would probably need an internal rechargeable lithium battery and the price would be much higher.

SONY claims 24 hours of battery life at 10mW output. Maximum output is 1 W/speaker or 2W. You can buy an external SONY adaptor (ACE60HG) for about $20; I think it's a 6V/700mA adaptor. SONY of course says not to use any other adaptor, a possibly compatible RadioShack universal charger is about $16 -- not much less. If you think you'll buy the charger, however, remember than the SRS-T77 comes with a power adaptor.

I started out using alkaline batteries. I'd forget to turn off the speakers and I was burning through batteries. I thought of buying a charger, but I had a much better idea.

I recommend, instead of the charger, buy some of the very high tech NiMH batteries and a charger. You can use these in all kinds of devices, and they last forever. They are designed to handle the power demands of a digital camera, so the spearkers are a piece of cake.

I ordered a RipVan 100 charger and 12 JetCell batteries (I paid for 8, 4 were freebies). You order this on the web, it's from a small eccentric business that provides terrific quality service. They seem to last a week or two in the speakers, and they recharge thousands of times. Definitely a better investment than yet another power adaptor.

With these NiMH batteries you can use your iPod as clock alarm while traveling. Just leave the speakers on overnight, the batteries will do fine.

"TRUE TO ITS NAME AND PRICED JUST RIGHT"
I just got my unit from J&R Music and Computer World through Amazon.com and I've been carrying them around with my portable minidisc player everywhere I go. They make an excellent tandem in terms of sound quality and portability.
The Sony SRS-T55 Personal Travel Speakers hold true to its name as personal travel speakers. They're lightweight and extremely portable due to its folding design. It has a provision for a 6 volt AC adapter and an easy flip top latch for 4 AA batteries if you're on the go. These speakers are ideal for a lap top or any portable audio equipment.
The sound quality is excellent considering its size. There is ample separation between the left and right channel which will satisfy most audiophiles. The sound of the treble frequencies are crisp and bright no matter what type of music you play in them. The bass is excellent considering that this is a small unit. One note though:You can't push the bass frequencies too low at a loud volume because this unit is designed to produce soft bass. Expect the sound to be distorted if you play the bass too loud.
The speakers work either as passive or active. I personally prefer to use it as an active speaker because the bass frequencies aren't produced clearly enough when it's used as a passive speaker. Although these speakers are rated as only 1 watt per channel, they're loud enough to be heard clearly at a radius of 12 feet at full volume. That's about a size of a tiny apartment or a medium-sized room.
For its portability, excellent sound quality, and fair price, you can't go wrong with this product.