The idea of using your smartphone as the brain to power larger gadgets is nothing new; the Motorola Atrix (and subsequent WebTop-compatible models) has its laptop dock, and Asus came up with the chunky-looking Padfone. At least Motorola gives you a few options for what you can plug the phone into, also offering its HD Multimedia Dock, but nothing we’ve seen so far has the sheer level of expandability as KT’s Spider Android phone, shown off at this year’s IFA.

Basically, the Spider is built around a Galaxy S2-ish smartphone, and offers an assortment of accessories the phone can be snapped into. Like the Motorolas, there’s a laptop option, and like the Asus, there’s a tablet that the phone can power. Other add-ons include a game controller shell that turns the phone into something that looks like an oversized PSP (or Atari Lynx, if your memory goes back that far).

KT hopes to introduce the Spider in Japan later this year. We think this is a fantastic concept, but why limit this modular design to what’s external to the phone? What about basing the system on a swappable motherboard/radio pair (in some sort of nice, durable module), so you’re not wasting the smartphone’s screen when it’s docked in things like the tablet shell? That would also let you update your smartphone’s display or replace a damaged one with ease. If smartphones are to eventually replace PCs, let’s see them offer some of these modular features that make computers so useful.