Let's say you wanted to leave me a tip with Bitcoin. How is that accomplished? You would:
1) Open your Bitcoin client;
2) Copy my wallet address from my blog;
3) Paste it into your client;
4) Enter the amount you wish to send;
5) Click "send".
Soon, it will happen like this:
1) Click the "leave a tip" link on my blog;
2) (Optional) Update the amount;
3) Click "send".
In the near-future, Bitcoin will be introducing a URI Scheme. Think of it like the Bitcoin version of an http link. The Bitcoin link will have a wallet address, amount, label ("The Bitcoin Trader") and message ("Your Blog is Awesome") encoded in the link, where you can change the message if desired. When it's clicked, it will trigger your client to launch and show you a dialog box with all of the information contained in the link. All you would do at that point is click "Send" and off you go!
Your client would then store the address and associate it with "The Bitcoin Trader." In the future, if you ever wanted to tip me again, you could just click "The Bitcoin Trader" in your client's address book, enter an amount, and click send. Suddenly, Bitcoin addresses are no longer a messy string of numbers and letters, but an actual name that you can read. The address is still there, of course, but there's no need to expose it to the user.
For the tech-savvy, it's added convenience, for the mainstream user, it's a giant leap toward acceptance of the technology.
Edit: While the above describes a way for you to "request" coins from someone by embedding a link in a website, email, or other, the URI Scheme can also be used to send Bitcoins. This would be accomplished by creating a public/private key-pair, sending coins to the keypair, and then providing a URI code to the receiver that contains the public/private key-pair. Again, all done with the click of a link!