I used Faendal as my follower for the first part of the game. Being able to give him stuff from my inventory was invaluable so I didn't have to repeatedly drop stuff while in the middle of a dungeon.

Then I dismissed Faendal and asked Lydia to join me. She's been a great follower EXCEPT two dialog options are missing. I can't interact with her inventory, and I can't dismiss her.

I even tried console commands like "set playerfollowercount to 0". The console accepts the command, but when I interact with Lydia nothing has changed. Having her stay in the house doesn't help, since other potential followers say I already have a follower.


UPDATE 1/3/2012:
Oops! The options to dismiss Lydia or share her inventory were there all along, hidden below the bottom of the dialog box. You can't see them unless you scroll down using the "D" key. Even in retrospect, it's not at all obvious they're there. I would never have known except Lydia dismissed herself when I completed the Companions quest line. Lydia started walking away, and it was clear she was no longer a follower. I chose Aela. She had only four dialogue choices, so the inventory and dismiss options were easy to see. Then it dawned on me what might have happened. I dismissed Aela, chose Lydia, and scrolled down. There they were.

Lydia is possessed by techno-demons.My Lydia I managed to get killed , and she respawned in my house in whiterun dead about a month later. There's something seriously buggy around that particular NPC.