I have a cube developed using SQL Server Analysis Services (2005). Its hooked up to an excel front end.
At the moment users have their own logon to the reporting server and access the reports that way. However, it would be nice of they could access the reports over the web.
Are there options for this? I could upgrade to 2008 if there was a compelling case.
The reporting server runs on IIS, so you'd need to treat this as any other IIS server. Common practice is to not expose a database server directly to the internet, so you would want to have a separate server hosting reporting services, which needs another SQL license - if you are not already configured that way.
I'm not sure if you're asking for a way to connect a local excel to the cube, or if you're just wanting to get into the reports interface.
I highly recommend using the aspxpivotgrid to expose your cube data within a web app. http://www.devexpress.com/Products/NET/Controls/ASP/Pivot_Grid/
note: not an employee of developerexpress