The point of getting a laptop is that it can do the job of these three things infinitely better than any keyboard will ever be able to do them (until they include a 15 inch screen, alphabetic keyboard and mouse). You just can't do effective sequencing and sampling any other way.

If a sequencer, sampler, harmonizer, and mp3 player are so important to your performance, you need to do it right. What exists on the keyboards in these areas is a joke - they are nowhere near the professional standards you can get on a laptop.

When I go to a performance, in addition to my Tyros 2, I take an iPod (even though the T2 has an audio player), I take a TC Helicon Voiceworks module (which is much more useful than anything on any keyboard because I have full access to the front panel), and I take my laptop which I use both as a sampler, and to record up to sixteen individual inputs onto separate tracks for post mixing.

I don't see any other way to do this without cutting corners.