Non-Market Content Publishing

In order to install apps from places other than the market, you need to enable that in Applications settings - allow unknown sources.

With the debug tools installed, you can install an apk from the command line by saying adb install my.apk.

You can also download an apk from a website, or email attachment, or post it in an alternate market.

For those cases, it needs to be signed with a key, but it doesn't need to be a release one, so the debug one that eclipse uses is fine.

To clarify and apply details to Mayra's comment, here are more detailed instructions for noobs like me 8^P

I did have to set my application settings to "allow unknown sources"

I connected my phone to my computer.

After XP opened the connection as an USB mass storage device, I could simply copy my .apk file to the SD card (which will be the drive name loaded against the USB mass storage device).

I went into the file, phone file app on the phone and selected the app.apk file and install.

Pretty simple.

As Mayra mentioned the debug tools, I didn't have to do anything as this seems to be the default setting. When I attached my phone to the PC, it gave me an option to turn off debug, but I ignored it. Everything worked out fine!