Yes, I thought this too. But, the tar file gets created wrong. It looks like this:

./web_dir
./cgi-bin
./www
./etc
[download]

Here's what I changed in my code:

...
chdir("$web_base/$web_to_del");
find(\&archive, ".");
...
[download]

When I un-tar it, all of the the files and directories underneath the web_dir are created separately instead of getting created under the web_dir.

Now if I just change into the directory directly above it, the tar file is created with just the web_dir and no other files or directories below it. Code:

...
chdir("$web_base");
find(\&archive, "$web_to_del");
...
[download]

I've tried a couple of other variations than this as well, but I get comparable (wrong) results.