Do you want to make sure your next lunch meeting with one of your LinkedIn connections is a home run?
This easy, five-minute trick may be so productive that you'll be happy to pick up the lunch tab.
Go to your lunch date's profile and scroll down to his/her connections. When you click the magnifying glass, 
a keyword search box will appear. Type in any keywords or series of keywords, (following regular Boolean search logic rules), and magically LinkedIn will reveal to you all the people in your connection's network that have those keywords anywhere in their profile.
If you want to filter further, just click Advanced Search. This will take you to the always helpful LinkedIn Advanced Search Page, but now you are only searching that one person's database.
Pretty cool, huh?      
connections searching advanced search 
Spend time reviewing the most interesting profiles. Take along a list of those folks, and be sure to bring them up during your lunch conversation. If your lunch date agrees to introduce you to some VIPs (potential customers, prospective employers, donors, etc.) or put in a good word for you, picking up the tab may be a small price to pay!
One caveat. If your connection has chosen to hide his/her 1st level connections, you will only be able to perform this search function on the connections you both have in common (shared connections).
Let me know how many lunches pay off in a big way for you!