If running macros fails then you can send me a request and i will send a file by email:(eerotibar@gmail.com)

"Maybe someone else have some lightning fast formula technique?"

You can try and explore the following, something different approach:

I tried this on my laptop with Excel 2007:

The following macro fills the column A with 1048574 random numbers between 1 and 1048574

Public Sub fillrandomnumbers()
Dim m As Long
m = 1048574
With Range("a1:a" & m)
.Formula = "=RandBetween(1,1048574)"
.Value = .Value
End With
End Sub

Now, it is needed to sort the list in ascending order!

Then, to get a unique list of numbers into column B run the following macro:

Sub uniquelist()
Dim s As Long
Dim v As Variant
Dim z As Long
s = 1048574
v = [a1]
Columns("A").Insert
With Range("a1:a" & s)
.Formula = "=if(b1<>b2,b2)"
.Value = .Value
.Sort Range("a1"), xlAscending
z = .SpecialCells(2, 3).Count
Range("c1:c" & z) = .Value
End With
Columns("A").Delete
[b1] = v
End Sub

It takes about 20-25 second to complete this huge task on my laptop.

Remarks:

The last macro works with strings as well. The sorting procedure can also be inside the macro. And there must be at least one free cell below the initial list.

See this post: http://www.get-digital-help.com/2010/07/17/create-dependent-drop-down-lists-containing-unique-distinct-values-in-excel/

In first one are names of people and they can occur many times.
In the second one there are different cities. So for each name one or more different cities can occur in second column.

The upper code does well when listing unique names. What if in certain cell I select from dropdown list one of these names and excel has to create secondary unique list (based on only one choosen name from column one). Any suggestions? Would mean a lot!!!

Advanced Filter uses your first value as a column header.

/Oscar

btw, do u know that the Adv Filter-unique value doesnt work if the first 2 values are the same?

e.g.

10001
10001
10001
10002
10002
10003
10004
10004
10005

generated list from Adv Filter are...

10001 <-repeat
10001 <-repeat
10002
10003
10004
10005

To remove "flipping" use: Application.ScreenUpdating = False

/Oscar

Sub AdvFilter()
'
' AdvFilter Macro
Sheets("VC").Select
Range("VC!A2").Select

Range(Selection, Selection.End(xlDown)).Select

Selection.AdvancedFilter Action:=xlFilterCopy, CopyToRange:=Range( _
"Calc!C2"), Unique:=True

Sheets("Chart").Select

End Sub

-----------

problem with Adv Filter is that it cant just pull data from another sheet. The sheet must be active before Adv Filter can be executed.

my rough tweak is to Select the VC sheet first, then let the Adv Filter routine run (generated on Calc sheet). Then change back to Chart sheet where the button is.

this creates a short sheet "flipping" when the button is created.

Sub AdvFilter()
'
' AdvFilter Macro

Range("VC!A2").Select

Range(Selection, Selection.End(xlDown)).Select

Selection.AdvancedFilter Action:=xlFilterCopy, CopyToRange:=Range( _
"Calc!C2"), Unique:=True

End Sub