Hi Monty, I have done it. I was adopted in 1973 several days after I was born to 16 year-old parents. Always known about it and it was never an issue but as I got into my 30s I became more and more curious.
As I was adopted in Scotland there is no requirement for compulsory counselling prior to receipt of birth cert so I sent away for and received my original birth cert last summer. It detailed my bm (birth mother) and birth f names, and through a bit of internet searching (and a few logical leaps) I found them.
They remained together after I was born and got married, then went on to have two other daughters - my sisters. We are in frequent contact and have met quite a few times, and all get on really well. I am now a big part of their lives and their family and it has added a whole new dimension to my life, as well as to my partner and our children's lives.
Advice: be prepared to feel things you didn't think you would feel. I am a very strong, stoic person, and I work in a field where I see both sides of adoption, so I was very prepared to find out the worst about my birth parents (drug addiction, prostitution etc etc). You may find something you don't like. Also, be prepared for your adopted parents to adversely react ... my mum has reacted very badly to this, despite being very amenable to the idea when I was younger. It has caused me a lot of grief and I have had to take more steps to reassure her than I ever thought I would. She is coming round now though, and I hope that she and bm will meet soon.
Finally, as several lovely posters in the Adoption board here told me: this is your thing. You didn't ask to be put in the situation of being adopted and you were the one whose choices were removed by everyone else.
Sorry its so long! Hope it helps, and good luck. Mine has been a hugely positive experience and I am grateful for that. If you want to chat feel free.
Scotsbird.