Ever since reading through the Complete Mage, two invocations have stuck with me.
All-Seeing Eyes, granting a +6 to Search and Spot checks for 24 hrs, and
Otherworldly Whispers, likewise +6 to Knowledge (arcana),(Planes),and(religion).
So let's take a human, add a level of paragon so he can add search to his class skills,
add 5 levels of warlock (I think 6th level seems to be where character concepts gel):
STR 8 -1
DEX 13 +1
CON 12 +1
INT 16 +3
CHA 14 +2
HP 5d6+14 (32hp)
Ranged +4 3d6 Eldritch Blast
Invocations :All-seeing eyes, Otherworldly whispers,
see the unseen
Decieve Item, DR 1/cold iron, Detect Magic (Sp) CL 5
Gather Information +5
Kn (Arcana) +14
Kn (Planes) +10
Kn (Religion) +10
Sense Motive +6
Investigate (Eberron), Investigator, Urban Tracking (UA), Skill Focus (UMD).
Hmm. what does he do, now?