Currently Being ModeratedFeb 5, 2013 8:56 AM (in response to saurabhaggarwal85)
Anywhere on the Internet, really. However, you would be better to upgrade from Leopard if possible as lots of Intel software which you could otherwise use is Snow Leopard and above. Purchasing Snow Leopard for £13.99 from the Apple Store would get you access to the App Store among other things (such as security updates, new features etc.) This would then open an upgrade path to Mountain Lion, again £13.99.