There's never been anything to stop takeaways & restaurants from listing their menus within display advertisements in Yellow Pages. The only real difference is that Yellow Pages now has a specific section which
only includes menus. (i.e. there's a 'Restaurant - Menus' section which is separate to the main 'Restaurants' section). The pages have a green & white chequerboard pattern on the edges, so that they're easy to find.
Our local Yellow Pages (Ipswich) have recently been delivered. (I know because my legs are still aching from delivering them and my head is still hurting from dealing with all of the problems of supervising deliveries by others!). The dates for other areas, up until March 2009, are listed here:
http://www.deya.co.uk/index.aspx?pageref=5300
Most of the vouchers in the Ipswich Yellow Pages are for things like double-glazing or driving lessons but there are a couple of restaurants with vouchers for 2-for-1 meal deals (not valid on takeaway orders) and one establishment giving 50% off on either restaurant or takeaway meals.
Incidentally, the paper version of Yellow Pages remains far superior, for many purposes, to Yell.com. That's because far fewer traders pay for advertising on Yell.com than in the book. For example, if you look under 'Garage Services' online, most of the listings are limited to name, address and phone number. If you look in the book, many traders have adverts telling you which services they offer and which makes they repair. Similarly, if you're looking for a dry-cleaners which also does repairs, you're far more likely to find an ad (with the relevant information), under 'Dry Cleaners', in the book than online.
Chris