So I've been putting in place a small scale Visitor ID System ('System' seems overkill for something this simple) from Dymo. Dymo also have another system - GuestGaurd which does something similar.

It does the basics very very well and its ideal for a small organisation - you just need a Windows PC capable of taking a Dymo USB label printer. The software acts as a simple kiosk which people can sign in and out of at reception (instead of filling in a Visitor Book). You can also hook up a USB camera and the application will allow you to print a picture to include on the label. Visitor reports can be printed at any time (on a normal printer). The printers are thermal which means you only need to keep it fed with labels rather than worrying about ink/toner.

The software can work in networked mode and it will allow someone at Reception to administer the system from their own PC as well as notifying staff when a visitor arrives - this mechanism was a little clunky to implement (relied on file shares rather than a standard windows messaging interface or email) and most IT people would be a little reluctant to network a system that was publicly accessible.

Still the basic configuration works really really well - Reception and their Visitors no longer have to mess around with the Visitor Book or its little labels.

This is kind of a long winded way of saying it would make a fantastic Open Source product idea - a LAMP based system (Linux, Apache, MySQL, PHP) with a Firefox front-end (in Kiosk mode). Visitors fill in a simple form when they arrive (some basic customisation could be carried out in the admin/reporting interface) - a list of who they're visiting could be pulled from an LDAP source with type-ahead auto complete and a simple email message could be sent to whoever they're visiting to inform them that their guest had arrived.

The back-end database would keep track of peoples comings and goings (and if you're a frequent visitor the system wouldn't make you sign in all over again) and let Reception print out visitor / fire-evacuation lists.

The admin / reporting interface would also just be a web form accessible to anyone supplying the appropriate username / password.

Enhancements could include a simple SMS gateway to text people when guests arrive or automatically call and inform them their guest is waiting for them. Then you could get really fancy and have modules that would integrate with CRM's to track client site visits.

You could get really fancy by allowing normal staff to 'pre-book' their own guests and automatically generate visitor labels which Reception could present to them when they arrive and send a reminder email when they're due to show up.

The LAMP advantage would be that you could install the entire system to a PC via bootable CD, configure it via the admin interface and then you're all set. As its all open source stuff it would be pretty simple to customise.