Thanks to developer Core Coders Ltd, the iPhone/iPod touch platform now has its own dedicated sampler.
Music Sampler is 8-note polyphonic and comes with 32 patches. These cover keyboard, woodwind, synth and other sounds.
Additionally, you can record your own samples in stereo (providing your iPod model supports recording, that is). The built-in keyboard covers the C1-C6 note range, and there's a key hold feature.
And that's about it, really; this isn't the most sophisticated sampler we've ever seen, a fact reflected in its $1.99/£1.19 price tag, but it's certainly a start. Get it now at the Apple App Store.