My T-Mobile G1 was recently stuck on the multicolored bootloader screen (with the first line reading DREA100 pvt 32b) and wouldn't load past that stage. I tried a hard reset and wiped everything clean, talked to T-Mobile tech support for over 30 minutes (we wiped everything clean 3 or 4 more times just in case) and it still wouldn't go past that page. All they could offer me was the phone number to the manufacturer HTC who said it would be anywhere from $50 - $250 to fix the phone, OR I could spend about $150+ on a new Android smartphone! Lucky me!
I wasn't about to take this lying down so I wanted to try anything I could to fix the situation. This is where the CyanogenMod comes in to play. I've known about this CyanogenMod for at least a year now, and I've known that it supposedly makes everything run a little faster and smoother and has a few extra bonuses, but I've always been a little scared to try it in case I bricked my phone. Well I'm proud to announce that I successfully installed the CyanogenMod on my phone last night and it's been working like a champ thus far. If anything changes I'll definitely report back but I'm glad I finally made the jump.
Should you do it if you own an Android phone? Well I consider myself fairly techy...I've installed some hard drives, graphics cards, and lots of RAM into desktop computers, but I've never actually BUILT a computer from scratch, so I'm nowhere near an IT professional. I'd only attempt it if you're familiar with how computers work, otherwise it might be best to stay away. It's not the hardest thing I've ever done from a computer standpoint, but there were a couple spots where it got a tad confusing. Just go to the link above and they lay it all out for you.
All in all, a bad experience with T-Mobile tech support (since they couldn't help me), but a good experience knowing my phone is able to easily take on a brand new custom operating system. Hooray Android!