NextUp.com

The speakers installed in laptops / tablet pc's are often very poor for an application like NextUp Talker. One way to solve the problem is to use external speakers. For external speakers, we need something small and light enough to carry around, and also produce sufficent volume and sound quality.

Here's a recommendation from one user:

JLab Audio BFB01 B-Flex Hi-Fi Stereo USB Laptop Speaker

These speakers are small (just one piece) and usb powered. Search on Jlab Audio BFB01 and you'll find places to buy online.

Any other suggestions / recommendations?

I have found that using the USB powered speakers made by Sony, model SRS-T10PC to be the best for my money. They are loud enough for me to be heard from 20 feet away in a board room filled with people and yet small enough to fit in to my pocket. And no batteries to worry about.
Doug

Another good speaker for laptops is the Tritton Model TRI-UA212. Also USB powered and one piece construction. It sells for about $30 at Newegg. (Originally posted in Sept 3, 2009 thread.)

I would recommend you Logitech V20 USB Speaker. It's really good for both laptop and tablet. It's light in weight. It's durable and portable so you can easily carry at anywhere. And it's response range is about 70Hz - 20kHz which gives excellent stereo sound quality. And come with 2 year warranty.