How to get Date Diff for Multiple Date (SQL)

Hi,
I trying to get the datediff (Today Date - ScanInDate). But the problem is i got few date to count. See the example below
Item                 ScanInDate
1               2012-10-11 19:40:41.000
2               2012-10-16 15:47:28.000
3               2012-10-11 19:43:22.000

The Output i want is 
Item        DateDiff
1                 6
2                 6
3                 1
Anyone can guide me?
Thanks.

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