$PHP_AUTOCONF errors on mac os x 10.7.3 when trying to install pecl extensions

I am trying to setup my machine with pecl_http and memcache and in both cases, I get similar errors. This is on MAC OS X 10.7.3 (lion) and I also have XCODE installed on it. I also installed Zend Server community edition before running these commands and have CFLAGS='-arch i386 -arch x86_64' environment variables set. So please help with what I need to do

bash-3.2# **sudo pecl install pecl_http-1.7.1**
downloading pecl_http-1.7.1.tgz ...
Starting to download pecl_http-1.7.1.tgz (174,098 bytes)
.....................................done: 174,098 bytes
71 source files, building
running: phpize
Configuring for:
PHP Api Version:         20090626
Zend Module Api No:      20090626
Zend Extension Api No:   220090626
Cannot find autoconf. Please check your autoconf installation and the
$PHP_AUTOCONF environment variable. Then, rerun this script.
ERROR: `phpize' failed

brew install autoconf

Much easier solution

You need to install autoconfig. I usually like to install libraries from source. So you can do the following:

curl -OL http://ftpmirror.gnu.org/autoconf/autoconf-latest.tar.gz
tar xzf autoconf-latest.tar.gz
cd autoconf-*
./configure --prefix=/usr/local
make
sudo make install

I just went through this with Mountain Lion.

On Mac OS X 10.8 situation is slightly different. Highly voted solution from Bob Spryn doesn't work, because it doesn't create symlinks, so after installing autoconf you should make them:

sudo ln -s /usr/local/Cellar/autoconf/2.69/bin/autoconf /usr/bin/autoconf
sudo ln -s /usr/local/Cellar/autoconf/2.69/bin/autoheader /usr/bin/autoheader

I know that this question was for 10.7, but I hope my answer is useful for someone on 10.8. :)

Updated: Also works on 10.10 Yosemite.

or

sudo port install autoconf

if you use macports

XCODE 4.3 doesn't put all the autoconf etc. tools in the Developer folder. It doesn't even create that folder in MACINTOSH HD. I had to downgrade to XCODE 4.2.1 which installs everything you need in the Developer folder and now I see no errors.

Also here is a useful reference.