How do I install and build against OpenSSL 1.0.0 on Ubuntu?

You can consider this a follow-up question to How do I install the OpenSSL C++ library on Ubuntu?

I'm trying to build some code on Ubuntu 10.04 LTS that requires OpenSSL 1.0.0.

Ubuntu 10.04 LTS comes with OpenSSL 0.9.8k:

$ openssl version
OpenSSL 0.9.8k 25 Mar 2009

So after running sudo apt-get install libssl-dev and building, running ldd confirms I've linked in 0.9.8:

$ ldd foo
        ...
        libssl.so.0.9.8 => /lib/i686/cmov/libssl.so.0.9.8 (0x00110000)
        ...
        libcrypto.so.0.9.8 => /lib/i686/cmov/libcrypto.so.0.9.8 (0x002b0000)
        ...

How do I install OpenSSL 1.0.0 and the 1.0.0 development package?

Update: I'm writing this update after reading SB's answer (but before trying it), because it's clear I need to explain that the obvious solution of downloading and installing OpenSSL 1.0.0 doesn't work:

After successfully doing the following (recommended in the INSTALL file):

  $ ./config
  $ make
  $ make test
  $ make install

...I still get:

OpenSSL 0.9.8k 25 Mar 2009

...and:

$ sudo apt-get install libssl-dev
Reading package lists... Done
Building dependency tree       
Reading state information... Done
libssl-dev is already the newest version.
The following packages were automatically installed and are no longer required:
  linux-headers-2.6.32-21 linux-headers-2.6.32-21-generic
Use 'apt-get autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

...and (just to make sure) after rebuilding my code, ldd still returns the same thing.

Update #2: I added the "-I/usr/local/ssl/include" and "-L