Why I'm going to vote Lib Dem

I'm not particularly keen on the idea of voting for Gordon Brown's New Labour, but as a low paid worker in receipt of Working Families Tax Credits I don't trust the Tory party either, even with their new 'non-nasty' image. The obvious solution is to vote for Nick Clegg and the Liberal Democrats, but it would be nice if there were more choice available other than the big 2 and slightly less big 1. There are other parties of course, but a vote for one of the smaller parties would seem like a wasted vote as they have very little chance of electoral success under the current voting system.
But it's precisely because of this last point - the notion that to vote for a small party (ie. any party other than Labour or Conservative or apparently, now, the Lib Dems) is to waste one's vote - that I have decided to vote for the Liberal Democrats; not necessarily out of a desire to see that party form the next government but in the hope that, in the event of a hung parliament with the Lib Dems holding the balance of power, they will use that power to push for a system of Proportional Representation to be brought in for future general elections. I voted Lib Dems in 2005 for the same reason, only this time I think there is far more chance of this actually coming to fruition. The introduction of PR would completely change the nature of politics in this country and would break the stranglehold of Labour and Conservative, making room for those who dissent from the views of the major parties to have their own ideas and opinions taken seriously within the political arena.
In other words, people such as myself, who might, all things being equal, be inclined to vote for one of the smaller parties, should, in my opinion, give serious thought to refraining from voting for the natural party of their choice in this election and consider instead voting tactically in order to bring about what would be far more amenable circumstances for said party at the next general election. Call it an electoral investment, with a very worthwhile dividend to be reaped in 4 or 5 years time. A vote for the Liberal Democrats in 2010 could be the springboard for a far more meaningful vote for one of the smaller parties in a few years time.