If you belong to a pool, the pool will be putting a vote into the blocks it finds (well, most pools will).  You could think of the pool as being your representative for the purposes of voting on the protocol upgrade.  If you mine solo, each block you find is effectively is a non vote and may hinder the rollout of either solution (because a super majority of mining capacity is needed before the change will go forward).

This is a huge issue right now. The first step is for everyone to stop using at least the top 3 biggest pools which are Deepbit, Slush and Guild. I know that not everyone will stop of course, but if enough of you do, we have at least limited the massive power they have over decisions right now.

The other step is to simply raise awareness among miners and pool operators. Miners need to consult their pool operator to find out what he/she is voting for and then change pool if you dislike the pool operators opinion.

Of course with p2pool anyone can vote for themselves but it's not necessary for everyone to use p2pool. It's VERY necessary however that we limit the power of the largest pools and start thinking about our votes.

For example I have mined at Bitlc.net (former Bitcoins.lc) for a long time now but I have no clue what the pool operator is thinking in regards to P2SH. When the voting period is on I will certainly want to know if the pool has the same opinion as I do, if it doesn't I will change my pool.

the point is it's not exactly a vote.
If you do nothing - your miner/client/software wont support the change
lets say 20% are for the change (and add the P2SH tag), 18% against and the others don't care.  In this case only 20% of the network will be able to handle the new type of transactions. so all of those who did nothing - are stopping the network from adapting to the change - even if they personally don't care.
the P2SH tag means "my miner can handle the new type of transactions".

eh?
i was talking about
and not the proposed voting scheme

STEPPING ON HIGH HORSE...

There is a widely-held illusion that it is necessary to have powerful miners. At some point, the necessity of slavery also seemed natural to every right thinking person.

Bitcoin holders are the group that should make decisions about bitcoin's future of bitcoin. The mining system hands this right to miners instead. Miners fortunes are not directly linked to bitcoin's future prospects. They can't be bothered to come up with an opinion or vote. Why would they? Why would anyone be surprised at this?

It is possible to use a system where long-term bitcoin holders vote to verify txns without engaging in mining (except perhaps in some quite modest way). Under this system, equilibrium long-run txn fees would be a fraction of what they will be under the current regime. Despite the cheap fees, the blockchain would remain just as secure. Major decisions would be made by the txn verifiers just like today. Except these people would care about making the right decisions. They would care because there fortunes would be directly linked to bitcoin's long-term success.

The alternative verification mechanism is known as "proof-of-stake". No one involved in the community is seriously interested in "proof-of-stake." This oversight is testimony to the narrow-mindedness of even gifted and innovative people.

GETTING OFF HIGH HORSE...

Sorry for the interruption, we will now return to regular programming...