"Mdworker" (Spotlight) stuck on Addressbook file.

It apparently is corrupted somehow, you will need to manually copy and paste the information in it out of it.

After making sure there is no other issues with your machine. (1-12)

Step by Step to fix your Mac

You can test if the above steps worked by using OnyX and it's Rebuild Spotlight option, after rebooting using OnyX, Spotlight will start all over again to rebuild and if the above steps worked to fix it then you won't have to continue further here.

If not and having adequate backups of your machine and data off the computer

Most commonly used backup methods

your going to need to recreate your user account to make a new addressbook.database.

I don't use AddresBook ever since Apple a long time ago decided to allow it to connect to the Internet, which I consider a serious privacy and personal security breach, but Apple puts ease of use ahead of that, then people wonder why they lost a contract because the competition hired a hacker.

But enough of that, once your user files (alone) are also backed up on a external storage drive (in addititon to other backups), you create another Admin account and log into it, delete the original one, reboot and recreate it and log back in, then import your data from the storage drive and reset User Permissions (see Step by Step)

This will rebuild the Addrebook dabase file in your user account name again and you import the data manually to eliminate the corruption, making sure there is no odd characters etc. that might be also causing your issues.

Generally, for me at least, Spotlight is invisible but I have had similar problems where it is constantly running. What has worked for me is to completely rebuild the Spotlight database for the volume. It can take a long time but if you let it run overnight it is not as intrusive. You might be able to do this with one of the utilities mentioned (I used SL Cache Cleaner) but you can also do this by adding your volume (hard drive) to the Spotlight Privacy panel and then removing it. You may have to quit and then relaunch System Preferences in between (the add and remove steps) but the mdworker process should fire up.

Quitting the Spotlight processes generally won't work; they will be automatically relaunced after a time.

Good analogy. Any chance you have some rogue Spotlight plugins (in /Library/Spotlight/, both in the root directory and your home user directory)? They have been known to cause problems.

These are standard. I have all of them except iWeb (which I don't have installed). I don't think the Spotlight directory in your user folder gets created unless you installed something that uses a custom plugin.

Okay, just to be sure, you have let the mdworker work away for a sufficiently long time (which can be hours)? Also, are you getting errors about these files in the Console? I looked just now and I also have a couple of recent "Error, could not create MachMessagePort for com.apple.AddressBook.abd" messages but Spotlight seems fine. Finally, Onyx probably can clear out all of the .DS_Store files. You will only lose window positions and sizes. As for the address book, you seem to have eliminated it, but you could try exporting your contacts (File->Export->Address Book Archive), deleting the contacts in Address Book, and then reimporting (File->Import). I am not sure that would clear out any corrupted entries. There are more aggressive means of rebuilding your address book, as pointed out by the other poster. You can also look here for some related information (although this note pertains to syncing): http://support.apple.com/kb/TS2481?viewlocale=en_US&locale=en_US. And one last stab, do you have anything in ~/library/caches/com.apple.addressbook/MetaData/)? You could delete that (metadata) and it should get rebuilt.

Deleting log files shouldn't cause a Mac to not boot. I wonder if there isn't some other issues here. I am sure you have rebooted a bunch of times but have you tried a safeboot: http://support.apple.com/kb/HT1455. Easy to do. This will do some directory checking and toss a few caches and disable startup and login items and only loads necessary kernel extesnsions. Spotlight should still be enabled (for Snow Leopard) and you can see what the processes are doing. For me (not in Safe Boot), the mds and mdsworker processes are using less than 100 MB of real memory but over 2.2 GB of virtual memory (but virtually no CPU cycles).

I can't vouch for Onyx but don't worry about the "DS_Store" files.

Leaving Spotlight disabled is not ideal. It is a great feature of OS X (just try doing a search on Windows to see how good Spotlight can be).

In my case, I don't reboot very often so I am sure the virtual memory usage creeps up.

Spotlight is a great help (when it is working properly).

Happy computing.