I know how to turn off one at a time.
- you right click on it
- go down to Hyperlink for expanded menu
- click on Remove Hyperlink
Then you find out word wrap has inexpicably been turned off as well, so you
- right click again
- go into Format
- tab Alignment
- re-select Wrap Text
- click OK.
Eight steps to disable a feature I never use, probably never will.
And I have to do this every time I enter an email address.
Otherwise, if enter the cell by clicking on it, it will call up my email package and start composing an email, and I have to wait for it to load and sign it off before I can continue.
I can’t see any way to turn this attribute off for all cells or groups of cells, like you can do with every other format attribute.
My version is Excel 2000 (9.0.2720)
This is absolutely amazing. At almost the exact same moment you posted this, I was cursing a blue streak at Excel over this exact issue. And to think, if I’d had the wisdom to be surfing the SDMB instead of trying to work, I could have commisserated with you in near real-time.
Live and learn, live and learn. 
Thanks! I can live with the first of the two suggestions made there,
namely just add a blank in front of the email text.
It’s easy enough and doesn’t mess up the printed list of my contact’s names and email addresses.
I realize now that I’d used that trick before to prevent certain text, like dates with dashes (6-30-2004), from becoming accidentally turned into calculations.
I only have 97 and XP so I’m not sure if this will work for you with 2000.
Enter the details in the cell.
Copy the content in the cell.
(You may need to then) Delete the content in the cell.
Edit | Paste Special | Values.
I know this will remove the hyperlink in 97 and XP, it may work for you too.
The ‘add a leading space’ trick is great for new entries.
For old ones, what I do is remove the link in the top cell of the email column, then right-click-drag to the end of the column and select ‘copy formats’
Also, if you enter the cell with an arrow key instead of clicking, the link won’t get triggered.