Lindy USB Guitar Cable 5m works without drivers, plug and play on XP and above.
On XP it's advisable to configure an ASIO driver such as ASIO4ALL (free, google it) on older operating systems to reduce latency to near zero if you are planning to use some sequencer software for recording and live monitoring. You will still get latency if you try to use only the standard XP Wave Device, ASIO drivers eliminate most of any lag.
Under Win7/Vista use the windows WaveRT device instead of Wave, and the ASIO driver should not be needed.
On latency, a slight improvement with the cable and XP+ASIO4ALL than I got via the onboard sound on my ASUS motherboard when using ASIO, but the cable does get far more signal out of the guitar and into the recording software (using Mixcraft 5 here).
On signal level - one thing to remember is that you will probably have to go into the audio settings on the PC (right-click the speaker, properties-> recording controls), enable advanced control viewing and in the advanced controls for the new USB sound device, DISABLE the AGC which is a software automatic gain control.
The levels coming from the cable dont need this, and you may need to reduce the volume slider to 20% or so (I did) to get the level low enough to be useable by your software.
Another "gotcha" to remember, is that the mini-soundcard that is inside the cable's USB plug has an unused and non-functioning sound output device built into it's chipset - if you get no sound from your normal speakers after installing this, youll need to check the sounds are going where you think they were - and disable the output device from windows. This is an input cable (unless you expect the guitar to work as a loudspeaker?) with a phoney output slot that you need to bypass or disable in windows or your software's settings.
Ok, in closing, happy with the cable. Given 4 stars, as I think some more instructions would be useful for us lesser mortals though the FAQ and forums are helpful.