Well gee, let's see, here's Apple's dilemma:
-They knew that the iPad would need more power to charge it
-They knew most people would want to hook the ipad into their computer via USB to sync
-They knew people would bitch and moan if they changed the "dock connector" standard currently in use with the iPod Touch, iPod, and iPhone
-They had to stick to the Apple "minimalist" design
So, they had to stick with USB, but unfortunately USB doesn't give off enough power, so they had to use a more powerful wall charger. The trade off is that using a standard dock/usb cable, it can only be a certain length before they have issues.
So... That is why we have a short cable... And why you can't charge efficiently using the USB on your computer.. Loose Loose, but also win/win given we get to keep the "Standards" of the dock connector and continue using all our USB cables that came with our other Apple products.
😉
However, I do have a solution for you. The power cable that comes with the Macbook/pro computers also works with the charging adapter for iPad. I have two of them, one behind my couch and one behind my pillow in bed, so that I can easily pop either my Macbook Pro charger into it, or the iPad charger.
🙂 That gives you much more length! Unfortunately if you don't buy a Macbook product, you'll need to buy the ipad power adapter with the longer cord here:
http://store.apple.com/us/product/MC359LL/A?mco=MTY3ODQ5OTY