Just a heads up about portable battery chargers.
I picked up 3 xpal lithium ion battery chargers from woot a year ago. They're great but they don't work with all devices. I'm confirming that they DO work with the sansa clip+. These are a god send for the clip+'s less than stellar battery life. I highly recommend picking one up if you use your player for extended periods like I do.
For those not in the know, these are medium sized external batteries that can charge a device via USB, or any proprietary socket. They come with a lot of commonly used tips and work great. They don't however work with all USB charging devices. I think some devices use different pin sets for charging than others. The one I bought for 5 dollars will charge my clip+ 3 and 1/2 times per charge.