This has long-since been replaced by the SX series. Check out the SX20, with 20x zoom and HD video. Here's what we had to say about the S5 when it was released back in May 2007:
Once more, Canon delves into the extended zoom field and comes up with a decent update to their already well-liked cameras. The S5 IS picks up where the S3 and S2 IS left off (what, no S4?), with a long 12x image stabilized zoom lens and 8 megapixel sensor. The biggest addition to this model is the Face Detection auto focus, which is smart enough to figure out that you're trying to take a picture of someone's face and not something ten feet behind them. For current S3 or S2 users, this isn't a tremendous step up from what you've already got, but if you're someone who hasn't yet experienced the impressive quality of the 'S' series yet, the S5 is a nice, fresh entry-point.