UK troops have it much easier than their US counterparts.
In general, they are still welcomed as liberators in the South by the vast majority of the population.
Militarily, their job is not a lot much different to what they were used to undertaking in Northern Ireland.
They patrol (normally with Iraqis) and generally just show a presence to reassure the local populations.
Behind the scenes the UK military is organising the building of an Iraqi security and intelligence force. They are also substancially involved in the
rebuilding of infrastructure - opening water pipelines etc.