Ubuntu and redirecting WiFi clients to .html page on desktop / laptop

view full story

http://askubuntu.com – Our church would like to set up a WiFi hotspot in the "sanctuary only" where wifi users are directed to an .html page on the desktop / laptop, running Ubuntu. Does anyone have very specific details on how we could make that work? What router works best (DD-WRT, etc) and the steps to doign that? Or, now anyone we can hire to confirgure a laptop and router to do this very thing? Thank you so much for your comments or suggestions. (HowTos)