Flashlight App

Put it on your phone, via USB. Then download an "app installer" from the market. That will scan your sd card for .apk files, which it will then install as apps. It's really pretty easy.
 
Click link, it will download, when finished, go to notification bar and click on it...it should pull up a box, read what it says and follow the instructions, super easy...
 
Another easy way is to email it to your gmail account, open the email, and there's an "Install" button if the attachment is an .apk. Might waste a bit of bandwidth, but it's insanely easy.
 
I just used the Color Flashlight from the market. Same one I've been using on my Hero. It does work the Led Flash light also.

Paul