Hi All,
Sorry to jump in on your post but hopefully this may help....
The most famous meeting point in London has to be under the clock at Waterloo Station, that said if you are going to be arriving at different times you may want a sit down wait. There are various bars at Waterloo...
http://www.beerintheevening.com/pubs/s/29/2968/Reef_Bar/Waterloo is on the station concourse, as is a Burger King (yuk!), Costa Coffee (though I tend to think Costa is rather expensive) and The Wellesley pub downstairs opposite platforms 3&4.....
http://fancyapint.com/pubs/pub3347.html Here's a pic of the station
http://www.urban75.org/vista/waterloo3.htmlI belong to a social networking club that frequently meet up in pubs, the organiser prints a couple of A4 sheets which are put on the pub table so we can be easily identified to newcomers. Yours could say something like PIOH Meeting Point.
Whenever I meet people near Waterloo we tend to end up at
http://www.viewlondon.co.uk/restaurants/the-fire-station-review-1804.html which is very close to the station. It's trendy fusion food not a traditional pub and the prices reflect this, so may not be best for those on a budget. A few minutes walk to Blackfriars Bridge brings you to a famous pub...
http://www.doggettscoatandbadge.co.uk/index.html. It's popular with tourists as it's right on the river, the food is reasonably priced but nothing to write home about.... just typical pub grub. If you walk along Upper Ground instead of Stamford Street to get there you'll pass Gabriel's Wharf on the way that has various eateries, but I haven't been there for several years so I'm not sure what's open at weekends and can only supply a link for you to research...
http://www.london-se1.co.uk/places/gabriels-wharf. You'll also pass
http://www.beerintheevening.com/pubs/s/30/3089/Mulberry_Bush/Southwark which was my regular lunchtime haunt when I worked in Upper Ground, but that was 15 years ago and times change! I've never been but believe this place is also popular
http://www.timeout.com/london/bars/reviews/11577.htmlOf course Waterloo is also right next to the Southbank Centre if you fancy a stroll after lunch, there's normally plenty going on there. Plus the London Eye is just a few minutes walk if you fancy it. Waterloo station is also very close to The Cut where there are quite a few bars & restaurants,
http://www.london-se1.co.uk/restaurants/info/111/the-cut-bar-and-restaurant at the Young Vic has had good reviews though I have never been.
Anyway, have fun