This may seem a bit evil - find a small space in the ex's house, eg inside a curtain rail, under the corner of a carpet, and stuff it with tuna. No immediate results but when it rots it will be disgusting. The other obvious one is to sign him/her up to as many internet mailing lists/porn sites for home as well as email delivery.
The best thing to do I think after a breakup is to get on with your life, act happy (not too happy or it'll b a giveaway) and don't let them see they've annoyed you. Either that or pull their best friend and say she/he's the best you've ever had!
Rise above whatever your ex has done . . . you'll be grateful in the future that you preserved your dignity and remained aloof. Or is that really boring advice? Sorry.
I'm with Ravenhair on this one - I lost a girlfriend to my 'best friend' and for literally years I planned various revenge scearios, but in the end, time heals, as it does, (just be aware that time is elastic!) and I am so glad I retained the dignity of silence, which means I could look either of them in the eye and watch them squirm a little, if we were to meet again.
Revenge is sweet sometimes. A colleague of mine had his comeuppance and I have to say he deserved it!
He was living with an American woman and managed to make one of her friends pregnant. Her revenge was to get some Hammerite paint and the whole apartment black! And I mean everything. She painted the TV, his clothes, the carpets, no surface was left unpainted. He learned his lesson, never to go out with Americans!
That aside, some people need to learn a lesson and giving out their (work?) e-mail address to hundreds of porn sites might do it. They'd have to know about the revenge though, so that the lesson can be learned.
I registered under her name at friendsreunited, and in (her) profile i put that i had discovered that i was a lesbian and was now living in Amsterdam with my girlfriend. (naughty boy) I feel... ashamed.
For something small, sign him up to every single junk mail thing you come across, catalogues inc the porn ones, petitions, free newsletters, anything you find at all. He will be inundated cr@p and it will go on for years, don't forget to include his mobile phone number as well.
Try to get over it your probably hurting yourself more than he would , but if you really want revenge and women always seem too..... get into his car and empty some full fat milk on the carpet or in the boot it stinks after a few days and carries on smelling after shampooing or for something really spectacular .... empty a box full of maggots into his heater vents then a few days later he has a car full of bluebottles.
I remember the revenge I got on the father of my kids after he dumped us when I was pregnant with the youngest after stealing our cds and money for food. I waited til after the baby was born and filled a pretty little pot with excrement from the baby's nappy, I then put the top on it and sent it to him. I am reliably informed that he opened it at the breakfast table while eating. It made me laugh for weeks and made my rejection a lot less painful. After all he'd given us a lot of cr@p so I was merely returning the favour.
Chilli's rubbed in underwear is a scream, or dog poo in the water tank is a favourite of mine... not that I'm bitter or anything.
Or turn the other cheek and be the bigger person!........ yadda yaddy yadda!
My ex giglfriend got the dog poo and I'm still laughing about it now 5 years on!!!.....Good luck
If you do this right, effects can last a lifetime - Be extremely courteous and friendly to your ex, as if nothing has happened. Then if they hook up with somebody new, act the same way towards them too. Doesn't seem like much I know, but unpredictable reactions and behaviour will mentally torture a person - particularly if they know they've wronged you! No guilt on your side, you're just being a decent person, right?
I must apologise in advance for being crude here, but my favourite for the dumped man is to be nice and friendly with your ex, wait 'til she's got a new fella in her life and then casually mention to Mr. New that next time he's kissing her to remember that your "member" has been in her mouth. And if you want to be really cruel, mention that the result of having your member in her mouth also meant that some of your... I think you know where I'm going with that!