Saw this film last Wednesday with my church - we booked the whole theatre out. It was very good though IMO, very inspiring, although not enough action and LOTS of talking and political debates.
Gets you thinking about what you're doing with your own life to change the world. I walked into the theatre thinking it was going to be about John Newton... the guy who wrote Amazing Grace so I thought it would have lots of shots of him being a slave trader and stuff but it's actually about William Wilberforce (cool name) and how he stood up against a whole nation for 2 decades working to abolish slavery. His passion was unbelievable! And he loved animals and was one of the founding members of the RSPCA too (not in movie though) but in the movie they show how he had loads and loads of pets... dogs running everywhere, an eagle like bird, and a hare.
And Ioan Gruffudd (pronouced Yo-wahn Griffith) is nice Always liked him... sucker for Welsh/Brits - Ewan McGregor, Colin Firth... ah Mr Darcy in the white shirt jumping into the lake for a swim ....

Overall, they could've done more to get a wider audience.. but they kept it to the barest minimum like maybe only 2-3 short flashback scenes of the slave trading conditions, the rest is talking. But they got their message across nontheless.

As it says at the end of the movie, slavery is still rampant throughout the world in one form or another and we can do our bit to end it.

This is a link to one of the most powerful documentaries I've seen. It's about children in Africa, goes for 55 mins and will make you !
Invisible Children