The 'anti-skip' of iPods is quite different from anti-skip in CDs, just because of the way data is read from the source.
In a CD, data is 'continually' read from the disc, and so jolting the player causes the reading to be interrupted, resulting in an audible 'skip'. Anti-Shock mechanisms on CDs work by grabbing larger 'chunks' of data at a time, and then playing from RAM, which, due to its non-mechanical nature, is not influenced by jolts in the same way. Because the data is stored in RAM, it eats more battery, which is why you can usually disable the feature, if you're sat at a desk for example.
In an iPod, the data is read from the hard-drive within the device, and because it is stored in a (compressed) media format (MP3, AAC or whatever), it usually needs more processing anyway (I think - my knowledge starts to fall down a bit). Anyway, the songs are stored in RAM, and the iPod can store a few there at a time, resulting in less HD access. (This is why you'll generally get better battery-life if you listen to albums at a time, because the HD requires less 'jumping-around' to get at the tracks it needs.) So most of the running of the iPod is from the RAM, which is non-mechanical and therefore not affected by jolts. It's only at the point where the iPod reads data from the HD that it is susceptible to 'mechanical' jolts, and seeing as it will usually try to queue things up before it needs to access them, it's usually not noticable. Hence you'll notice the HD spinning up every now-and-then through an album - most likely half-way through a song.
I've prolly made quite a few mistakes here, I kind of know 'how' these things work in principle, but without intracate knowledge of the situation.
