what I don't understand is how miners keep joining BTCguild when they have many other pools with lower hashrate, some even join the private pool GHash.IO !!!!
This is a flaw of a decentralized currency powered by democracy. The following is a nice video on explaining the implications of this effect:
http://www.youtube.com/watch?v=s7tWHJfhiyo
In essence, those who are worrying about a single pool getting to 51% (i.e. "first past the post") will go to the second largest pool, instead to the smaller ones. Essentially only two pools will be left.
Same with the two-party system in America.
When I minded I used P2Pool https://en.bitcoin.it/wiki/P2Pool
I remember mining at P2pool as well, but the problem at the time was dust, I would pay crazy fees for transactions, although I was looking at P2pool and the Litecoin Devs with the Bitcoin devs were giving funds to make a better software that solves many of the problems, I don't know how is it today with P2Pool since I stopped mining a long time ago but I think this problem is solved.
Hint: you can still use P2pool even if the dust issue still exist, the key to reduce this problem is to use coin control, you simply take all inputs to one transaction and pay the fee only once, this is what I was doing...
and P2Pool is the only solution for decentralized mining so I don't know if miners understand that and at least give it a try !