Most of the time the phones have a recovery mode. My scariest was with my USB interfaced Treo 650 that I thought I bricked, but I kid you not, like a week before I did it, shadowmite came out with USB tools for it instead of having to get a serial cable and I revived it. Sometimes a little luck goes a long way.
BTW...I just put my phone in bootloader mode. I'm ready.
