Hi Rob,
You can eaily redirect to SiteRoot + "Default.aspx?pageid=" + pageID.ToString()
but that doesn't preserve the friendly url.
I'm going to add a helper method to make it easy to get the friendly url for the current page. It will be in svn within the next few days. I'll add it to SiteUtils so you'll be able to call it like
string currentPageUrl = SiteUtils.GetFriendlyUrl(CacheHelper.GetCurrentPage());
Something I've been meaning to do that your question has reminded me to go ahead and do.
Thanks,
Joe