20,000 songs? Not nearly enough. $24.99 a year? Way too spendy. Unlimited and $20 a year? That's a little better, at least, and that's what Amazon just moved to. Taking a step up from its previous $20 for 20GB plan, the former bookseller is now letting new subscribers get any amount of storage they want for that price -- unlimited for .mp3 and .m4a files, anyway. Naturally this means any songs purchased through Amazon MP3 will also be stored for to an infinite extent, not counting against your all-important quota. This is a "limited time" kind of deal, so if you've been on the fence now's the time to click that cart, but there's another new feature that isn't going away: Cloud Player for Web on iPad. This lets you play your cloud tunes through Safari and that, combined with the whole unlimited storage thing, should ease any nagging feelings of regret you've been suffering since budgetary pressures talked you into the 16GB model.