It is Worksheet Protection
As an experiment:
Open a new worksheet
Whichever Excel version (2003/2007) you have; start the process of
worksheet protection
You should see a dialog in which you can specify is uses can move to
locked, to unlocked cell, to other object

best wishes
--
Bernard Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme

"Silverstreak" wrote in message
...
I received a spreadsheet in which you can only click into certain cells
and
enter data. But I can't even click into the rest of the cells containing
formulas etc at all.

It isn't like protection, where you can click into the locked cells, but
when you try to enter data a message appears indicating that the cell is
locked. In the spreadsheet I received you simply cannot even click in the
cells.

What is this feature, and how do I turn it on? (it is functioning in both
Excel 2003 and 2007).

Any advice you can provide would be greatly appreciated....Thanks