Since about 2006/2007, reducing power consumption (heat output) has been the most important factor driving the colo market. The general solution has been towards virtualisation, in order to reduce idle electricity usage. In alphabetical order, the following are all good quality virtual, Xen, KVM or similar providers based in the United Kingdom and run by clued up people whom exist in real-life. They are probably all equally good and I'm purposefully not going to recommend anyone over anyone else! (alphabetical order):
Likely to be out of date eg: internet evolves fast.
People are always asking about getting decent co-location for their personal boxen and hosting for a small company (or co-operative) to buy rack-space from to co-host/co-locate 1U/2U/3U 19inch rackmount machines. They're all in E14 at the heart of the UK internet in London's Docklands... Basically there are three providing inexpensive ("cheap") colocation:
Jonathan Riddell has done a page on Colo providers in Scotland.
† nb. Until 2004 Your ISP could not charge you for IP address-space assignments, only based on what you could justify (RIPE-283 form). This was restriction was withdrawn at RIPE-47 in 2004.
Back to the rest of Paul Sladen.
2004 April 26th
Wed, 30 Apr 2003 23:24:08 GMT - Black Cat up their bandwidth allowance to 40GB/month
Mon, 30 Jun 2003 14:57:13 BST - Added reference to Spodcolo as a Jump brand
Sat, 27 Dec 2003 20:31:14 GMT - RIPE-219 superseded by RIPE-283 - Thanks to Andy Mulholland
Mon, 26 Apr 2004 14:37:32 BST - Black Cat up their bandwidth allowance to 100GB/month, dropped Easynet and both went full-time.
Wed, 28 Apr 2004 20:50:10 BST - Jump up their bandwidth allowance to 60GB/month.
Sun, 27 Jun 2004 21:08:02 +0100 - Black Cat get their 217.147.80.0/20.
2009-11-15 - Add virtual server providers.
2015-10-09 - Jump increased baseline virtual machine specifications.
2015-10-26 - Jump colo/Ripe-283 updates.