Callmeed, I am looking to use Slicehost, how is your experience with them? Thanks.
Slicehost is wonderful ... they aren't a "managed" company but their support is great. They reply to tickets fast and have a support chatroom. They also have some great articles for getting slices prepped for php/rails/django apps on different distros: http://articles.slicehost.com/ I wont name names, but I've had better support from Slicehost than a managed RoR hosting company that costs 5x.
Slicehost are great, but afaik they are hosted in the US. Rackspace and Serverbeach good in the UK.