jessica
this would be really messy but at our senior grad party we had an icecream party where you drew a number, each number corralated with a bowls, a spoon, the actual icecream, whip cream, sprinkles, cherries, and sauce. you would draw a number and that's what you would get first, it was actually really fun but might be a little messy for the lobby.
Go for it with the ice cream! I guess it depends on the type of girl you're recruiting...we had one for a spring COB one year and it was great. I think most of my girls can appreciate a PNM who can enjoy ice cream and not get wigged out by a spill...laughing it off is a good sign.
Something you could do instead of games is watch movies...isn't that what girls do when they have boy troubles? Eat ice cream and watch chick flicks?
Maybe you could play bingo with the toppings. You could also divide girls up by their ice cream choice (say all the chocolates here, all the vanillas there, all the strawberries...) and play a game that could use teams, like Trivial Pursuit or Scattergories, something that everyone can get into.
We did an ice cream social for informal recruitment for both Winter and Spring. We just sat around and chatted while eating, and afterwards watched TV. It was for the third (last) day, though. It was a good chance to just get to talk to the girls. Surprisingly it wasn't very messy. We had our girls serving, asking what PNMs wanted. Kept things neat. It worked very well, it was a good chance to get to talk to the girls. Everyone loves ice cream, and if a girl doesn't know what to say she can take a bite to think!
what about a byob....bring your own banana...party? You could have arts and crafts supplies for the girls to decorate. you could give prizes for the best dressed banana, etc.