For the last years, I carry a rather bulky key ring. Attached to an old Mercedes Benz star emblem (with the star long broken) were no fewer than 15 keys and a bottle opener:
It weighted 187g and contained a lot of keys I nearly never used or even couldn't remember what they were for anyway. Inspired by the EDC Blog I decided to revamp the key ring and replace unneeded keys with some more useful tools. This is what I carry now:
I'm down to six keys (apartment and office) and the whole ring now weighs 122g including the tools. Of these I selected the three following after some careful review studying and spending hours on different EDC1) sites.
For the keyring itself I decided for a Drosselmeyer Free-Key. It's similar to a simple key ring, but has a cool system for adding and removing keys without breaking your finger nails.
For now I'm pretty happy with the outcome, but might want to experiment with different tools in the future. An iGo MicroUSB charger cable or a mini prybar tool might be useful. If you have any useful tools on your keyring I missed, please let me know.