Does anyone know of a better contacts manager? Hopefully one that can show google groups. I would really like the ability to link my Facebook friends with my contacts, sort of like the way the HTC Sense and Moto Blur does it.
I don't know if there's one that does what you want, but there is "Contacts GroupU" that works with Groups, and "Star Contacts" that is more of a stock replacement. I use both.
I may not fully understand your question but you can add your facebook contacts through the contacts settings. I did it on accident and my contacts were flooded with everyone in my facebook friends. If that is what you are looking for, you do it through contacts}settings}display options.
The stock contacts can be linked with facebook and twitter, just sign in to the apps and there are options to sync your contacts. If they do not automatically sync you can manually link the contacts, contacts > edit contact > menu > join.
I do think sense did a better job of automatically matching contacts than the stock contacts app on Froyo, I had to manually link more contacts on the G2 than on the Mytouch Slide.