Did you know that you can actually use data compression in a database with compatibility mode 2000 as long as you use SQL server 2008 Enterprise edition? Add DATA_COMPRESSION=PAGE in the WITH clause when you create the index. When you use data compression you will save a lot of disk space and io operations, but you will get some CPU overhead. Make sure you have enough CPU resources before you implement compression. If you need some help with indexing strategies and compression, feel free to contact our SQL server consultants.