Why we need Bing, Yahoo and the other search engines

I confess that I'm one of that minority of users that doesn't use Google as my first choice search engine. For the past few years I've been using the various incarnations of Microsofts' search offering, now called Bing. That's not to say that I think the previous efforts were any better than Google, but for most of my searches it would normally find what I wanted; with Google being the backup choice when I couldn't, not that Google came up with the answers every time either.
But I persevered in my stubborn way and now that Bing has been released I really do feel like I'm using the superior product. I like the features on offer, particularly the 'preview' feature which pops up when the mouse hovers to the right of the search result items. Nor have I needed to use Google since Bing's release, the results have been spot on and I've generally found what I wanted far more easily than in the past.
As much as I like Bing this article isn't about singing it's praises. We need Bing, Yahoo and all the other search engines to balance the monopoly that Google is fast becoming. I saw some statistics the other day which said that 65% of all searches are conducted using Google with some regions showing a far higher percentage than that. That begs the question if it is really healthy for access to the planets information to be entrusted to one company?
How many times have we heard stories of small businesses that have been almost bankrupted because the Google search algorithms were changed and their site disappeared from the listings, having previously been quite high? It is certainly a worry for any business that relies heavily on search engine traffic.
Let us not forget also that Google is a business, and a very successful one at that, if their dominance of the search engine market grows further, how safe will we be from search results being skewed by competitive advantage or some hare brained marketing idea? I think we need other search engines to keep the results that we get from any of them honest, after all we must be able to trust those results or the search will be meaningless.
Personally, I don't think any of them would be that stupid because if they were found out users would turn away from them in droves. But what if it was the only search engine that anybody on the planet really knew about? What if there were no other alternatives? Would we be able to trust them then?