I have an electric pump in each of the cars - for what they cost nowadays (a basic one is about £15), it's not worth risking getting a flat and not being able to inflate it. On more than one occasion, I've got a slow puncture but been able to re-inflate, carry on the journey, then get it fixed at my leisure
However, my transporter trailer tyres run at around 75psi and I did have trouble finding one that could pump this high. In the end I bought a Sealey one (I think) which lives in the Discovery and can inflate them fully, although they take around 10 minutes from flat to get to this pressure !
I'm not keen on using the cigarette lighter though, prefering to connect directly to the battery terminals, to avoid any chance of melting the car's loom. It's also good to keep the engine running, as the slightly higher voltage helps reduce the required current slightly
