1. you need create a web deploy project, if you didn't have that,please install the web deployment plug-in.

For Visual Studio 2005, the plug-in can be downloaded here.

For Visual Studio 2008, the plug-in can be downloaded here.

2. Configure your deploy project properties like below.

3. after build, you will get a single assembly CommonVoiceUC.dll,
in you new web site, add it to your reference.

4. in your aspx page, use it like regular Customer Controls.
<%@ Register Assembly="CommonVoiceUC" Namespace="CVUC" TagPrefix="cvuc" %>
<cvuc:CvDistributionGroupUpdateUC runat="server" ID="test" />

so this way you can very easy create a lot of customer controls with lots of Html tag or css in it. and it very easy for other application to use it.
the bad thing is if the control have other components, for example "Telerik.Web.UI.dll", and other site want to reuse this control was using a different version of Telerik control.
the conflicts will happen.