Data validation list

[rayslinky]

In Office 2007/2008, I was able to use the following formula to create a list for data validation:
=INDEX(B2:B79,MATCH(TRUE,B2:B79<>B2,0)-1):INDEX(B2:B79,MATCH(TRUE,B2:B79<>B2,0))

My B column contains 2 unique values, so this chose 2 next to each other that had different values. In Excel 2010, I get the error: "You may not use unions, intersections, or array constants for data validation criteria". Does anyone know how to select the two unique values in the form of a list for data validation purposes?

 

[Progrower]

See this post.
http://www.mrexcel.com/forum/showthread.php?t=493661

 

[rayslinky]

I tried this, but I get duplicates. My column contains only 2 values, but they are repeated 80 or so times, so the drop down that the data validation generates contains 80 of the two values. Is there any way to get just the two unique values?