seriously: I've been searching for a while but have found no answer, is there any way to put apps onto the phone from my computer? I don't have a wireless network at home so I can only connect through the usb cable.
It would be easiest to pick up a cheap wireless access point, or if you have Windows 7 you can get a wifi adapter and create a virtual access point. There are apparently ways to do "reverse tethering" through the USB cable but they involve a lot of messing around, and it's very handy to have wifi access for the phone around the house anyway.
You can install APKs from the USB card but you can't download them (legitimately) for many market apps.