[Exodus]

I've personally had some fun with Glitches in my games and like some other posters I treat them as "you succeed BUT", they add flavor and allow me to screw up a flawless plan without having to pull something out of my backside. My players have learned how to think on their feet and adapt to situations quickly so that when the disguise glitch accidentally has them wearing gang colors in the wrong part of town they can adapt to it.

On a side note, when a player rolls a glitch/critical glitch, try just jotting down some notes on when the glitch happened, what the player was trying to do etc. Then you can make your players sweat about it while you think something up and play off their paranoia.

[Crash_00]

A great example of that would be The Big Hit. Wait, we just kidnapped boss/fixers god daughter...drek.

[Shinobi Killfist]

I really am not a fan of the mechanics of the glitch, critical glitch in SR4.  Odd pools are better than even, small but supposedly somewhat competent pools have a really high glitch rate etc.  So I generally tone down the effects as much as I can, I trend more towards the amusing set back than to the you are screwed. 

[Crash_00]

I really hate the mechanics of the critical glitch and think that it pops up way to often for professional skill level dice pools RAW. I've gone back to the old SR3 way of thinking with them, and only have critical glitches occur if all the dice come up 1s. This makes it incredibly rare for anyone competent to actually completely botch. I think their is little to be gained from a botch feature in an RPG as it hurts players far worse than NPCs (which characters make the most roles in a game).

That said, as long as the GM doesn't treat every glitch as a "your dead now" effect, I'm all for them. I don't think normal glitches are meant to be deadly so much as inconvenience. I do vary the glitch according to the degree of success and the nature of the roll.

Runner is running down the sidewalk  in pouring rain chasing a ganger and glitches his athletics test.

On a Crit glitch he may have sprained his ankle (-2 pain modifier to all rolls where he's moving for 2 days), or maybe he slipped and sprawled into the latino gangers next to the alley. Now he's being chased by gangers while hes chasing a different ganger.

On a normal glitch he could bump into an old lady (who then remembers that damn orc that made me spill my cat food) or smack his elbow on a mailbox (-1 pain modifier for two minutes).

The mechanics are not fairly distributed on every dice pool, but I don't really see them ever being in a system that uses dice (especially restricted to only D6s).

[Mystic]

Ya know, I've been using "glitiches" for years in other games and havent found any real adverse effects to my players. Now granted, the glitch/whatever usually is the result of a players bad choices. For example, I had an old Star Wars D6 game with a house rule concerning the "wild die". Long story short, player rolls a 1 on the WD, they tell me.  I roll a d6. On a 2-5, its usually something that will complicate things like a blaster powerpack going bad, etc. On a 1, its considered a catastrophic failure. On a 6, the player succeedes despite themselves.

One example, a Jawa player is running from CorSec through an alley, decides to dive through a conveniently open window. He failed his roll and roled a 1-1 on his wild die: the result: his aim was off and smacked the side of the building. And he only had a 1d+2 for strength to resist damage...and rolled a two. Night night.

Second example, something more SR-ish. PC is in a club, chatting up a hottie he homes to schmooze for some info (and maybe something more). He's too busy trying his spheel and the club is to noisy that he misses that the hottie in question has been trying to tell him she has a boyfriend....a very BIG boyfriend who is now standing behind him about to put his fist into his face.

Third example: Sammie Ben Strong is trying to jump on a moving remote-controlled tractor trailor as part of an infiltration. Now, he misses, and misses BAD. He falls to the ground, absorbes the damage, but glitches.  OK, how to handle this. Hmmmm how about the SMGs he was carrying suddenly go off because the impact had that one in a million thing happen where the smartlink egaged the remote firing command and now an entire mag had been emptied. Think of that scene from Im Gonna Git You Suka.

Fourth example: group of runners makes some INSANE stealth checks to remain undetected in a warehouse, but realize their ride is now compromised and have to secure alternate transportation. They hotwire a van, but glitch. The result: the vehicle reverse alarm, you know that BEEP BEEP BEEP, goes off and every sec-guard knows where they are. Oops.

Thing is, I use glitches not to punish the players, but most often as comic relief unless the glitch in question is something that would REEEEEEALY F-up the senerio. Its like in every TV show or movie where the hero has a "oops" moment. I can see how it could be abused, but if you have a good GM, then they can be quite entertaining for everyone.

[Seeker]

My first game I ran for the group I'm GM'ing now.

A Troll Bouncer at a club doesn't let the party in, until he notices a  female Troll wearing a slinky Zoe dress in the party.  She decided she's going to seduce him.

She defaults on her charisma for not having any con skill, and I give her an extra die for the dress.  She gets a success, but glitches.

The troll lets her in, nobody else.  I decide that the troll was really enamored with her.  After her gets off his shift, and she's long gone, he actively seeks out her commcode.  The glitch just means he found it.

Now, she doesn't know this yet, but I'm gonna let her roleplay it out.  Hey, her glitch might actually get her a contact.  Or a stalker, if she's not willing to pay him any mind whatsoever.

So, I personally think that character glitches should be something that modifies the story.. maybe sometime offering a bit more challenge.