BTC (Bitcoin) mining, join a pool. Nevermind probability, lady luck with ensure you go nuts trying to find a block with anything short of a serious farm. I think someone said 10Ghash/s... well, lol, is all I can say
NMC (Namecoin) mining, join a pool for now, but come the next difficulty adjustment your soloing will pay off well.
Actually, don't bother with NMC mining. Price is dropping, and BTC mining is still more profitable.... justhttp://dot-bit.org/forum/index.php?sid=3d0b7f46b241fe8ec6cf20741dfe7634
You'll find info on how to solo mine in there. I got in on The Great NMC Run... my own name for it.... infact I was there a week before the rush.... and done very well, thank you
NMC Exchange: https://exchange.bitparking.com/main
NMC n BTC Difficultyhttp://dot-bit.org/tools/nextDifficulty.php
Keep an eye on that to see which might be best to mine, BTC or NMC
I think that's enough posting for me... time to chill with a beer and a *ahem* while I watch some telly