fun challenges for party with range of optimization

[therakishrogue]

So, I'm GMing a 3.5 campaign for a party of four with a wide range of optimization level. We're at level 3 right now, and the characters are a human druid/wizard (aiming for theurge), a gnome battlemage who's player is new to the game, a skill-focused thief (aiming for shadowdancer) of a homebrew drow variant played by a serious roleplay enthusiast, and a scout/barbarian goliath (aiming for dervish) played by a player who knows far more about the numbers game than I do.
My question is how do I make challenging combat encounters for the more optimized players without killing the others. So far the campaign has consisted mostly of the goliath bulldozing through opposition until he drops, and then the rest of the party grabbing him and running for their lives. I'd like to mix it up for them. Any ideas for tailoring encounters to suit everyone's talents at the same time?

[AMFV]

So, I'm GMing a 3.5 campaign for a party of four with a wide range of optimization level. We're at level 3 right now, and the characters are a human druid/wizard (aiming for theurge), a gnome battlemage who's player is new to the game, a skill-focused thief (aiming for shadowdancer) of a homebrew drow variant played by a serious roleplay enthusiast, and a scout/barbarian goliath (aiming for dervish) played by a player who knows far more about the numbers game than I do.
My question is how do I make challenging combat encounters for the more optimized players without killing the others. So far the campaign has consisted mostly of the goliath bulldozing through opposition until he drops, and then the rest of the party grabbing him and running for their lives. I'd like to mix it up for them. Any ideas for tailoring encounters to suit everyone's talents at the same time?

Well the best way to do that is probably to involve a few challenges that are more interesting for the other players. The goliath is pretty good at killing stuff, but not so good at dealing with magical problems, not good at dealing with incorporeal enemies, not good at dealing with spellcasters.

You could probably incorporate some of those things and it would create more tension for the other players. Also flying enemies is good in this respect.

I'd probably include some traps or puzzle rooms, since those are likely to cater to the non-goliath party members as well.

[Sir Chuckles]

A Ghost, or something similar.
Why?

Because it can fly and is, as others have said, incorporeal. That lessens the power of the Goliath, while letting the Druid/Wizard and Warmage shine. Said Druid/Wizard clearly doesn't have turn attempts like a Cleric, as well, so it doesn't put too much light on him.

Put it inside, giving the Thief the ability to climb the walls. Add in traps that he can disarm or jury rig to fire at the ghost. Add some areas in which he can use Disable Device or another skill to set a platform, so that he can drop a rope for the Goliath or catch him when he jumps (so that he's not completely out of the fight). Bonus rule of cool points if you homebrew a magic item that makes his Jump and/or Climb checks Free/Swift/Immediate Actions (to lessen the action economy, so he can still consistently attack. I'd make it a Swift, so it's less abusable. I'd also make it a potion and give two, so the Rogue gets the same treatment).

You could also use a dragon with a bumload of HP and an upped flight manueverability. Or really anything that can fly effectively.

Give whatever they fight a cast of Dispel Magic prepared. Aside from the fact that it's generally a good idea to have prepared, if the Goliath gets Fly cast on him (or a potion, more likely) you can laugh as he takes fall damage.