wired network cards

Although this device is a very nifty idea, since this device is only written to the USB 1.1 standard, its top transfer speed will be 12Mbps, which is will only give you 2Mbps more throughput when connected to a 100Mbps network, so beware of that. If it was USB 2.0, then it could more than handle the 100Mbps speed.

I have one of these in my computer junk drawer (a collection of adapters, plugs, gender changers, card readers & cables....sounds a bit like a circus side show but it never fails me!) and have found it useful on several occasions. At this price, it is worth having around.
Basically, you can plug your ethernet cable into the adapter and then insert the plug end into any USB receptacle on your machine (such as on a laptop or a TIVO, etc.). It therefore makes buying (or having) an ethernet card superfluous. It has connection & data transfer LEDs to tell you you've contacted the network, though these are not really necessary. No set up is required either, just plug and go.
As far as I can see, the connection is quite as stable as any hard wired one, and while it's true a USB 2.0-compliant adapter would allow for greater transfer speeds, on our network it has performed flawlessly.

As others have noticed, fragile design. I broke it, and I was being gentle. Had to replace it with same model, though, since USB to Ethernet adaptors are not easy to come by (TiVo, thanks a lot for making customers go through this).

I long for TiVo's next generation, when I hope they'll have an ethernet plug in the back.

If you're stuck getting this one, like me, be *extremely* careful plugging it in.