Unless you're keen on "permanently" fixing it, that is. There's more than a few places that'll tell you to use WD-40 on a stuck iPhone home button, but this is a very poor idea indeed. Here's why. It seems to make sense -- WD-40 is great for unsticking all sorts of things, and the one constantly used part of an iPhone is the home button. It even ran on Lifehacker not that long ago, but as iMore points out, it's a phenomenally bad idea. Not just because it'd invalidate your warranty, or indeed as one Lifehacker reader pointed out, because it'd leave you with fingers that reeked of WD-40. It's more simple than that. WD-40 is a liquid that you'd be spraying around the home button and near the docking connector.
Liquids and your iPhone shouldn't mix. although as Cameron points out below, WD40 is at least non-conductive.
Of more long term concern, the reason why WD-40 works is because it's a solvent. Solvents, as the name suggests, dissolve solutes, and one of the solutes that WD-40 will work on is plastic. There's a lot of plastic in the iPhone, including the home button itself.
So in other words, don't use WD-40 to fix a stuck home button. Possibly some isopropyl alcohol cleaner if you must, but I'd suggest lining up for a Genius bar appointment first instead. [iMore]