Well, can you still use fastboot? If so, search on XDA Developers for the man himself EzTerry. He has a nice tutorial for installing a new Radio and SPL for the HTC Dream (dont worry, not the Nexus One, i've checked it
) Follow that and you can flash your recovery again, your ROM (Even CM7) and as a bonus: You get more then 10 mb of RAM!!!!!!! BUT if not, you'll have to put the DREAIMG.nbh (google it) to your sdcard and install it using the bootloader BUT you'll be back where you started, with Android 1.0!!!!!! (No root access, no nothing, but a standard recovery) AND, a bricked phone won't start up, won't go to recovery AND to bootloader and the most common reason for bricking your phone is: 1. Not seeing what file you are downloading AND flashing it
2. Putting it in the right order!!!! SO easy but SO many bricks!!!! That's all you need to know!!! Good luck!