I had this 60,000+ transaction file and needed to find the one transaction whos length was greater than the rest. Tried eyeballing it and found nothing; was about to write a quick C# console app when I decided to try out Powershell.

I came across this one line command in the comments of the correct answer and modified it slightly to print the transaction instead of a message.

Get-Content "C:\FileToLookAt.txt" | ? { $_.length -gt 272 } | % { Write-Host $_ }