[Desire HD General] Jason1978:
Hi,

Will try and answer or confirm what you know...

1: If you are in the UK, a mobile phone given with a contract is owner by the person who takes out the contract. The operator has no hold on it, even if you cancel the contract. If you cancel you owe the operator the cancellation fee which will cover the cost of the handset.

2: I have found the best way to save your contacts is "in the cloud" as it were. My contacts are saved as Google contacts and as such when you link your account with your phone, the contacts reappear if you have say updated to a new ROM (If you are going to install a new ROM, it is advised to factory reset your phone etc prior to flashing a ROM). The added bonus of using Google is the speed in which the contacts get readded to the phone, or and as a backup, as they are always in the cloud. If you dont want to do this, then you can store on the phone and back them up to your PC using the HTC Sync software. You SIM card has very limited storage, and if you have multiple numbers against a contact, email addresses, other information on a contact etc, you will not be able to store that on your SIM.

3: Obtaining ROOT gives access to the root of the android system. You can do everything you could before ROOT, so the only reason really you might want to unroot is if you wanted to return your phone under warranty. You can apply ROMs when you have root, whether they are official or not. You may lose root if the ROM being applied is official. There are also guides to remove root.

4: Which ROMs are best are down to personal preference. You first need to decide if you happy with just the android/google standard apps or whether you cannot live without the HTC sense interface, and then decide on an appropriate ROM. There is a list on the Wiki.

5: You can only have one ROM at a time. Installing a new one overwrites the old one. If the custom ROM is rooted, and I think most of them are, then you do not lose root. The whole process of install a custom ROM is not just about rooting the phone, you also need to install a alternate recovery console, clockworkmod recovery being the one. Again you need to follow the guides, but if you have installed or your phone came with ROM version 1.72.x then I believe there is no way currently to root the phone, which is the first step.

6: For overclocking, there have been a few kernels released which you flash in addition to the ROM. These give you access to higher CPU frequencies. The voltage required is dealt with by the kernel. You can set the speed via a program called SetCPU. The Buzz kernel for example is overclocked to 1.53GHz I think. At stock speed and up to a certain speed, the processor is actually undervolted, which should give better battery life. There would be a bigger drain on the battery at higher clock speeds obviously. You can set profiles on SetCPU, like what speeds to use when the screen is off, which in my experience have made the battery last longer. With any processor being overclocked, you are pushing the values that the processor was marketed for, so this can affect the life of the processor.

Hope that helps...

Overall though, looks like you can't do anything yet anyway.

Jason