Everything online can be faked. Here's how.

Very briefly, and without giving away too many details in case a scammer does sneak in here, here are the methods that everything online can be faked.

Webcam - easy/free. All you need is to find some footage of the person you want to be and some free software to create a "fake webcam". You can also find screen capture software for free in order to record the webcam of the person you're talking to.

Email addresses - very easy/free. You can literally put any email address in as your "sent from" address. The secret to spotting it is to look for the "reply to" address.

Photos - free/easy. Google any celeb or porn star and there can be thousands of photos of them the scammer can use. Go to any social networking site and people are posting up hundreds of photos of themselves. We strongly recommend you watermark any photos you put online to stop them being reused without your knowledge or permission. 

Phone numbers - fairly easy/from free up. With programs like Skype or redirect sites like K7, you can have a virtual number from almost anywhere in the world. I once called Pinky and spoofed the White House's number, so anything is possible. Be aware that calling these numbers will cost a LOT of money.

Voice - very easy to complicated/from free up. A scammer could simply speak in a higher pitch, or he could use a voice morpher. There are voice morphing programs that range from free up and with various levels of sophistication.

Websites - tricky/from free up. There are free hosts that will let you create a site from a template. Registering a domain name is only around $10 a year. Other methods of hosting the site is to hide it in a genuine site that's been hacked or even to pay for hosting using stolen credit card details. Making a site does need a little more skill, but there are a lot of ready made templates you can use, or you can steal the code for another site and alter it for your own needs.