Should I give up my pending I-485?

Dear Pjiang and others,

I filed my I-140 and I-485 in 2005 and I-140 NIW was approved in 2006, but my I-485 is still pending. I'm going to move back to China very soon and not sure what to do with my pending I-485. I've heard that I can change to Consular Processing of I-485, but during that process, I'll very likely get denied if I apply for other types of US visa. I don't see I'll come back to work in US in the near future, but will have some business trips to US. What's the best solution for me? Should I give up my pending I-485 (and how)? On the other hand, if I somehow come back to work in US in the future and I already give up my I-485 this time, can I keep my PD if I apply for I-485 again? many thanks for your suggestions!