I've just bought four sets of these lights as I wanted to put some festive lights in my windows but don't have enough convenient plug sockets and didn't really want trailing extention leads all over the place.
I agree with the previous review, they look lovely and bright, are great quality and the range of effects is a bonus, though personally I only use two settings. There is also an 'off' button ( I wasn't actually sure there would be!) so you can save battery power if you don't want them on during the day.
The cable is clear, which helps it blend better with whatever you are fixing the lights to.
The length is just right for my needs as I only wanted to run them along the bottom of my windows, but I'm sure they would look stunning entwined in Christmas wreaths or garlands, stair bannisters, along mantlepieces etc, or even in a clear vase. I can't comment on the battery life as I haven't had them long enough, but I've used them for a week, putting them on every evening since dusk for about 7 hours and they're still going.
Definately recommend these lights, but I suggest you buy them directly from the lights4fun website, as P&P is much lower.
UPDATE DECEMBER 2009.
Having used them for two Christmases now, I'm not quite so happy with these and would probably now say 'buy with caution'. Out of my four sets only two are still working, and the plastic battery covers on all four sets don't fit properly. I've contacted Lights4fun directly but have had no response (surprise suprise.)