You can use Chip Pearson's Cell View addin to find out the character it is:
http://www.cpearson.com/excel/CellView.htm

If those box characters are char(10)'s (alt-enters), you can use
edit|Replace
what: ctrl-j
with: (spacebar??)
replace all

If that box character is something else, you may need a macro:

Option Explicit
Sub cleanEmUp()

Dim myBadChars As Variant
Dim myGoodChars As Variant
Dim iCtr As Long

myBadChars = Array(Chr(13)) '<--What showed up in CellView?

myGoodChars = Array(" ")

If UBound(myGoodChars) < UBound(myBadChars) Then
MsgBox "Design error!"
Exit Sub
End If

For iCtr = LBound(myBadChars) To UBound(myBadChars)
ActiveSheet.Cells.Replace What:=myBadChars(iCtr), _
Replacement:=myGoodChars(iCtr), _
LookAt:=xlPart, SearchOrder:=xlByRows, _
MatchCase:=False
Next iCtr

End Sub

If you're new to macros, you may want to read David McRitchie's intro at:
http://www.mvps.org/dmcritchie/excel/getstarted.htm

Tonya wrote:

I have a document that was provided to me which I have to make some changes
to and save as a text file for importing into a database. However, there are
breaks after each line signified by a small square. I want to remove all
those breaks because when saving as a txt file, it thinks it is a real break.
How can I remove those crazy little squares.

--

Dave Peterson