GoogleSomeone, who must have been terribly hungry, once said: “There is no such thing as a free lunch.” Well, for those of you who have always maintained that nothing can ever be free forever — even products by Internet behemoth Google — you’ve got it spot on.

In what must be a tacit acknowledgment that even they cannot endlessly increase the amount of free storage for its popular products such as Gmail, Google has just launched a new service that allows you to purchase more storage space. At the moment, you can use this additional storage with Gmail and Picasa Web Albums.

This extra storage acts as overflow when you run out of free storage space in either service. If you’ve filled your free storage (2.8 GB and counting for Gmail or 1 GB for Picasa Web Albums), you’ll automatically use your purchased space to store more pictures and messages up to your new storage limit.

According to the official Google Blog, A simple way to get more storage:

… in a few hours we’ll be rolling out extra storage that you can purchase to use across several Google products (today, Picasa Web Albums and Gmail; soon, other applications like Google Docs & Spreadsheets). We’ll update this post as soon as we’re ready to take your order.

The post has since been updated and you can now purchase additional storage space. Price plans start from $20 a year for an additional 6 GB and goes up to $500 a year for 250 GB.

You can read more on purchasing storage space from Google Answers, or check out your current storage usage here.

Obviously, paying for services that one uses is fundamental of basic economics. Still, you wonder about the shape (and storage space) of things to come. How would Hotmail and Yahoo! Mail react to Google’s selling of storage space?