No one can guarantee you your "virual execution" will go virual. No one. That said, there are best practices that have come about that we can look to to increase our odds. My favorite is the 3 S's: simple, socialable, shareable.
Simple: Keep it simple stupid. How many times have you sent a cool gadget or website to your friend only to here, "I don't get it". The old saying in the Linux community is something to the effect of, "Linux will never experience wide spread distribution until my grandmother can figure out how to use it." If your target doesn't immediately understand what is going on with your execution in under 3 seconds, you are on the wrong track.
Socialable: This should also be thought of as (while we are making up words) 'personalizable'. You will increase your odds of going viral by allowing the user(s) to personalize the experience. Nothing makes us laugh more than when you can turn 'it' into an inside joke, make it relevant to something funny that happened last night, or just straight up humiliate your friends in that pointed manner that only you can.
Shareable: If you can't share it, it can't be viral. Make it easy for them. Make sure there is a 'send-to-friend' feature. Make sure the links can be pasted into emails. Make sure the emails don't get trapped by spam filters (have your IT guys check his mail servers here).
The people at Oddcast get this to a 'T'. From Elf-Yourself to Age-o-Matic these guys exemplify the 3-S's perfectly. The most well known is probably Monk-e-Mail. It is as simple as 1-2-3-4-5. It is socialable: add your own message in Step 3. Finally, it's shareable: the send-to-a-friend feature is right there at Step 5.
If there was one last thing to add, it would be to make sure you have a seed strategy. You have got to raise awareness of your execution to a minimal level. IF it is going to go viral, it will only after it has hit a critical mass. If you have an email list, use it. You could also make some small media buys such as Google Adwords or Facebook Social Ads. You can also find some popular, on topic blog entries to comment on with a link.
Remember, no one can promise something will go viral but a good place to start is with the 3-S's and a good seed strategy.
If you are thinking about making your foray into social media, you need to be thinking PR.