I dated and married a colleague.. and after changing company we are still colleagues. We want to remain like that, if we do not decide to divorce ;-)
And hey, it's fun. Didn't take toll on productivity or anything. You get much more things to talk about if you are in the same office. And I think companies like that too (atleast in software, they do). It means longer commitment to the company.
Well, working seperately can be done anytime. But we are enjoying working together while we have the opportunity.
Now thts a strict No-No......... its very difficult to keep control of your emotions,,hence for me its a NO NO. Its less messier too... But i know of cases tht can handle it well,,,so,if u r good,,go ahead ,,have a ball.
its impossible to date your colleague without affecting your professional relationaship!!even u repeat it innumerable number of times, the truth would not change that u tend to expect more and give less which becomes even more apparent when u r dating someone at the ver place u work!! apart from this, there will alawys b a tendency to keep a check on the other one(again distracting you from ur work) and also, to get bored of spending so much time with each other!!