I just came across an announcement for Traveler's Choice Ultra-Compact Stereo Speakers by Targus.

While that product page was short on details, I found another product page (in korean) with more information and I like the specs.

193 grams (USB-powered), plus an optional 4xAAA battery pack. The use of standard AA/AAA batteries is great since I already carry a travel charger when on longer trips.

The speakers on my N800 are woefully low in volume so perhaps a set of such compact travel speakers could make it more useful as an on-the-road media player.

Cool... Find a good source yet?

They're on ebay.com.sg for ~24 USD + shipping, anyway, which seems reasonable.

I'm thinking these could help out with a bike sound system.

The price looks very reasonable indeed. I haven't been out looking for these yet, but it could be useful to keep the product code handy: TARGUS AEM08AP

A quick search didn't come up with any reviews, but they seem to be quite widely available.

I bought my Nokia MD-3 Portable Stereo Speakers because they were cheap (bin-end at the airport's Dixons shop). I have to say that I'm impressed by how much better they sound compared to the competition (for a similar price/size).

However I do have to adjust the equalizer settings when I use them, because the small speakers (2 Watts) cannot handle the loud bass sounds.

Overall I'm very happy with the M-3: I love the analog sliding volume control, the audio cable is robust and stows away neatly (3.5mm standard connector), the mains charger is good to have (in fact it's the same as for the N810) but I can also use 3 regular AA batteries so it's very versatile.

Since I am in Korea at the moment I ordered a set from the Korean website. Should have them in a couple of days. I'm still looking for a set of small travel speakers with decent sound, maybe these will fit the bill. Thanks to Peet for the point out.