Give out a different GMail email address to each potential spammer (web form) without creating a new (dummy) email address each time

When you give a company or web page or "friend" your email address you never really know if it's going to be "given" (OK, sold) to a spam company who thinks that you'll be interested in their latest and greatest product or service.
Well, here's a simple way of finding out who sold your email address to that spammer.... and when they do send you spam, it's easy to set your email program to filter those pesky emails out of your InBox.

Each time you give your email address away (read as: "each time you fill in your email address into a form") add a suffix to your username in your email address that will identify who the email is coming from. So, that's RealEmail+Suffix@gmail.com

For example, if your real email address is FredFlintstone@gmail.com
When filling in a form on site SiteXYZ, then fill in your email address as FredFlintstone+SiteXYZ@gmail.com
So, if you get from that address, you will know that SiteXYZ betrayed your trust and gave your email address to those spammers.

Now, to make that spam go away.... Just create a filter, and make everything that is sent to FredFlintstone+SiteXYZ@gmail.com go to the trash.
This way all the spam will be deleted automatically.

To create a filter see: GMail help on using filters