Although it's dull to start a round-up of music gadgets with an iPod, there's no denying that Apple's stranglehold on the MP3 player market has strengthened over the last couple of years. Pre-nano, we saw competition from other manufacturers in the flash-based sector of the market, but now Apple has the leading hard-drive player and the leading flash player (it's also number one in the 'clip-on players with no screen' arena, but there aren't any competitors there). We favour the nano over the 5.5G iPod (aka the iPod video), because it's smaller, cooler and better looking, but if you have a large music collection or want to watch video clips on the go, the bigger 'Pod is the one for you.
When you get home with your shiny new iPod, the first thing you should do is throw out the headphones that came with it. Listening to music with the bundled earbuds is like trying to hear birdsong from the shoulder of the M25. For a good-value upgrade, consider the Sennheiser CX300 earbuds, which give you significantly better sound at a reasonable price (there's something faintly ludicrous about spending more on your 'phones than you did on your Mp3 player, but if money really is no object, take a look at the Shure E500PTH earbuds).
Earbuds aren't exactly optimal when you're relaxing on the sofa, and they certainly don't work for dinner-party music, so you might also want a speaker system. The big white brick that is the Apple iPod Hi-Fi provides surprisingly good sound for a one-box system. For excellent tone and accuracy in a compact and elegant package, we remain fond of the Eclipse TD 307PA system, which combines two egg-shaped speakers with a conical amp.
Alternatively, you could beam digital music from your computer to your hi-fi using a pair of Sonos ZP80 ZonePlayers. Sonos' system transfers music around your house wirelessly, enabling you to listen to music and Internet radio wherever you want. If you don't have a hi-fi, the Sonos ZP100 ZonePlayer (reviewed as part of the Sonos Digital Music System) includes an amp, so you just need to connect it to a pair of speakers.