Partly because I'd like to get in on the fun.
Partly because I'd like to see what can be done with a Warlock.

Assume I want to make the party think of me as useful.
I also want to stay out of melee, being painfully aware of my squishiness relative to the heavy hitters.

I made a point of acquiring at least 16 Dex.

Pimp me please.

For pure blasting, a psionic race wouldn't be too bad (Xeph?). This allows you to take Psionic Shot, which is a very nice way of adding some damage. Point Blank Shot at first level. You'll end up with Dex 18 from the very start, which should serve you to keep you from harm and allow you to actually hit stuff, especially if it's within 30 feet.

And keeping "pimp" in mind, a multi-class with bard (Eldritch Theurge later) for some mean social-fu would be an interesting alternative.

Edit: The latter was something I kept in mind while planning a character for a Wilderlands game. The concept was a Chosen of Odin, in his guise as a wandering stranger...

I don't remember for sure, but I think you can treat the Warlock's Eldritch Blast as a ranged weapon for some feats.  If that's the case, then like for most archer types, Point Blank Shot followed by Precise Shot is probably a good idea.

Xeph resemble humanoid insects, don't they? It fits my image of him. An outsider among the huge hulking humans, so he wants especially hard to make the party like him.

I like the ideas so far.

Have to be away for a few hours but I'll look in as soon as I come back.

..Cerulean Buglike.

Quote from: Cerulean LionPartly because I'd like to get in on the fun.
Partly because I'd like to see what can be done with a Warlock.

Assume I want to make the party think of me as useful.
I also want to stay out of melee, being painfully aware of my squishiness relative to the heavy hitters.

I made a point of acquiring at least 16 Dex.

Pimp me please.

At first level, select Baleful Utterance.  In case you don't have your book handy, this means you can now cast shatter at will.  Humanoid opponents lose.

As if that wasn't enough, whenever you destroy an item someone was carrying, he has to save versus daze (1 round) and deafness (1 minute).

Did I mention you can cast it at will?

Baleful Utterance is a goodness.
My Warlock is looking better.

Well, confer with your DM first. Shatter is a rather peculiar spell, especially the "single object" rule is often the target of heated discussions. If for your DM the hinges on a door or the lock on a chest (no padlock) are isolated objects, have fun. Otherwise...

Personally, even if I'd take that, I'd take it later. It has  a saving throw, so a few levels help there. If you're really going for blaster, Eldritch Spear might be a better choice, as range really helps. If you're taking a Xeph, you're a rather quick bugger, more range on your blasts helps you (ab)use that...

Your main advantage is that Eldritch Blast is a ranged touch attack so the target AC of your enemies is likely to be low. This advantage is eliminated if some ignorant meat shield wades into melee with your target granting it a +4AC bonus and giving you a -4 penalty for firing inot melee. For that reason, playing a human with Point Blank Shot and Precise Shot feats is a good option. However, at higher levels these feats are less useful so I'd only recommend taking them if a) your GM is allowing retraining (per PHBII or other rules) or b) you don't anticipate the campaign lasting too long.

I'd second Baleful Utterance as a good pick of invocation. Eldritch Spear look nice on paper, but combat rarely takes place at such range at low levels.

What does anyone think of the Essence Invocations for Eldritch Blast? Is it worth spending a slot for the ability to put "sickened" or "shaken" conditions on a Blasted target?

Well, vitriolic blast is worth it -- Spell Resistance is the biggest detriment to a blasting warlock. I'm not too fond of the rest of them. Getting more target is okay, so the invocations that change the blast shape might be worth getting. Most conditions aren't that universal to make them worthwile.

On the other hand, one of my players was recently testing a Dragon Something (don't remember the exact name) from the recent Dragon Magic book, basically a dragon-themed warlock. His breath weapon could slow down enemies (replacing damage, IIRC) and even worked partly on a failed saving throw. For a non-martial build that was pretty okay.

I have to admit that I like blasters. Defeating your enemies by battlefield control or save-or-die spells just doesn't feel as satisfying as by pure damage output. It also feels less "dirty" on a mechanical level.

EDIT: There's one big advantage of those invocations: They change the equivalent spell level of your blast. Without those, even with 20d6 coming at the enemy, a minor globe of invulnerability will protect him. On the other hand, there are feats for spell-like abilities that allow you to apply meta-magic effects to the x times per day (probably x = 3). You'll probably have more feats to spend than invocations, especially if you want some cool bits and not just blasting.