You are innocently trying to find a file on your computer and you come across some very odd things that weren't there before.  I am not talking about viruses. I am talking about emails that have been moved to secret folders, chat software hidden amongst your better half's work files, maybe even pornographic pictures.  Still not sure if he/she is cheating, here are some sure fire hints to tell if they are and if this isn't enough information, I have included some additional links. 

~Finding chat software hidden in a secret location.

~finding raunchy email from people you have never heard of.  BTW, 9 out of 10 times they will use code and and they will use fake names.

~Finding Semi nude, nude and pornographic amateur pictures and videos.

~When checking your browser history files you come across links to chat room that promote illicit sex or pornographic chats (sometimes innocent, but a large majority of people that visit these types of site tend to keep going back)

~Do you find your mate disappearing at strange hours during the night (like when you should be sleeping), or making excuses to stay up later than you.

~Do  you ever catch you partner by surprise when they are on the computer and they quickly close the window they were in.

~Are they spending hours and hours on the computer (and I don't mean doing work).  They may also get testy when you come near them.  They will want privacy more and more when they are on the computer.

~Weird charges on your credit cards and when you confront your mate they make up a really lame and unbelievable excuse (sadly they usually try to make you look stupid)

~Not wanting sex or wanting to spend to time with you.  

~Mood changes are a huge give away.  Unless you are female and then you can blame PMS.  I use that one for everything. 

In a lot of cases those who are being affected, tend to think that they are not desirable to their partner any more and because of this they were driven to cheat.   I must stress NEVER THINK THIS!!! EVER!!!  The majority of the time you are not even the issue.  Your partner has found a new thrill in their life.  There are many reasons that this will happen!!!  Sometimes this is the Gods telling you it is time to move on.  This isn't always the case, relationships can be saved through intervention and counseling.   I have included some links, to help you catch your partner, and links with more information on cyber cheating as well as some other resources. 

Want to catch your partner in the act.  Here are links to software you could use.

http://www.spy-software-download.com/

http://www.intelsoft2000.com/software_w/monitoring_

software_w/cyber_informer.htm

Links to sites with more information on Cyber cheating.

http://www.pan-arts.com/era/perspectives/cheating.htm

http://www.infidelity-infidelity.com/cheating_

infidelity_stories.htm

http://ursu.uregina.ca/~carillon/Sept12.96/feature

/feature1.html

http://www.afamilyaffair.com/wa7.htm

http://www.hermarriage.com/hard/oct01/cyberaffair.shtml

http://www.mountainhighpub.com/cheating.html

http://clubs.yahoo.com/clubs/hurtbycybercheating