I recently learned about the magic of the IF statement. No, not as a conditional in a programming language, but as a formula in a spreadsheet.

You know those stupid #DIV/0! errors you get after you’ve masterfully crafted a beautiful spreadsheet that doesn’t have any data in it yet?

This fixes that.

Here’s the syntax¹:

=IF(CONDITIONAL, THEN, ELSE)

For example, if you want to display the results of A1 / A2 in A3, you’d use the following formula in A3:

=IF(A2=0, "n/a", A1/A2)

The second parameter (“n/a” above) can be anything you want, and is only displayed if the conditional is true.

1. At least in Google Docs. ↩

I have a BearExtender n3 that I use to access weak (or far away) wifi networks. When I’m using it I usually share my Internet connection through Airport.

Except this stopped working after I upgraded to Snow Leopard.

After Googling for eons, I finally came across a fix. Though it was advertised for connecting a Squeezebox or Xbox 360, it works just as well for MacBooks and iPhones.

Start Internet Sharing
This will create a file called “bootpd.plist” in /etc. Copy this file to your desktop.¹

Stop Internet Sharing
Open “bootpd.plist” in a text editor. Look for a key called “reply_threshold_seconds” near the bottom of the file. It should have an integer value of 4. Change this value to 0 and copy the file back to /etc.

When you restart Internet Sharing everything should work again.²

1. To get to /etc, open a new Finder window, type command-shift-g and enter “/etc” in the text field. ↩
2. If it still doesn’t work, check “bootpd.plist” in /etc and make sure “reply_threshold_seconds” is still set to 0. ↩