Earliest ways to get Scent/Mindsight/Lifesense/etc.?

[Mister Freeze]

I realized that the bestial domain grants scent, so if you prefer you can pick up planar touchstone  and choose the bestial domain, and only need to invest 1 feat to get scent. 

[Gavinfoxx]

Eh, Bestial domain is BoVD... don't really like most of that book...  So for my psionic guy, pick up Trandsimensional Power as the level 5 feat, then?

[phaedrusxy]

Warlock gives Scent as a least Invocation (available at 1st level), and Detect Magic at will at 2nd level. A Warlock 6 qualifies for Mindbender if you take the Charm Invocation (lesser, available at 6th). With a one-level Mindbender dip, you qalify for taking Mindsight as your 9th level feat.
Being a Necropolitan is just as good as usual, and if your base race is Human, just snag Lifesense with your bonus feat.
IIRC, Warlocks qualify for the Obtain Familiar feat. Pick that, and Improved Familiar, and choose a Beguiler (monster, not class; Shining South), which has constant True Seeing.

That should start you off nicely enough.

Always on See Invisible can be had through the least invocation See the Unseen, which a level 1 Warlock or Dragonfire Adept can take.  Warlock's Devil Sight invocation can also be useful as it lets you pierce even magical darkness.

If you want to be arcane, use Improved Familiar to grab a pseudodragon and psy-ref / DCS its feats to Mindsight perhaps.  Or an Imp works as well.

For 10,000 GP you can get a draconic graft of the Glaring Eye to get 30' blindsense.  Blindfold of True Darkness from MIC is 9,000 and gives you always on 30' blindsight for 9,000, but you're completely blind beyond 30'.

Tremorsense can be gotten through the Landshark Boots soulmeld, or be insectile (+2 LA) for 60' tremorsense (among other things).

Now I want to play a "radar" warlock...

[TSS]

Bump because I got a kick out of this thread.

[snakeman830]

What about the various Detects? Detect Magic, Detect Animals or Plants, Detect Chaos, Detect Law, Detect Evil, Detect Good, Detect Poison, Detect Undead, etc.? Is there any way to get always on versions of as many of those as possible?

Before Permanency comes online, I mean.

Minimum of 2 rounds of Concentration before you learn anything more than "Presence or abscense of X in the area" and only has a 60ft range.

Hmmmm, can't get Shape Soulmeld if undead...

You can, if you have to, using the Undead Meldshaper feat (lets you use incarnum as an undead and bases it on Wis instead of Con), but it's not generally worth it.

No, you really can't.  Undead Meldshaper doesn't do anything for changing feat prerequisites.  It would only allow an Undead with Meldshaper levels to shape their soulmelds and determine the maximum number of soulmelds shaped.  It would also work for anything with racial meldshaping ability (like an Incarnum Dragon), but the Shape Soulmeld feat doesn't play well with it.