zCat - 12:33 pm on Jul 26, 2005 (gmt 0)

If you use FireFox / Mozilla (probably a good idea if you have surfing kids anyway) there's an extension which enables you to define your own user agent strings:

[extensionroom.mozdev.org...]

A somewhat more ambitious solution would be to set up a local HTTP proxy for your home network which dynamically rewrites the user agent on all outgoing HTTP requests. Assuming your router can't do such a thing that means you'd probably need to set up a dedicated Linux box or something.