Now that I think of - it must have been an address that I entered long time ago. Coz my chronlogy was:
1. learned about bitcoin
2. experimented with wallet software
3. experimented with mining software using the crappy card I have at work
4. researched AMD cards and bought a couple and started mining
so somewhere along 2. or 3. I probably entered the address into that field... Now I probably need to search my work computer for wallet software... hopefully I ll be able to find the one I used to obtain that address...
I think what got me confused is the "step by step" instructions on slush's site:
How do I get started?
1. Install Bitcoin miner on your computer
2. Sign up with a bitcoin.cz account
3. Run miner
Which is wrong. It should be:
1. Install a WALLET, get a BTC address
2. Sign up with bitcoin.cz, use the address
3. Install and run a Bitcoin miner on your computer