Incorporeal/Ethereal at low levels

[Elfinor]

What are some low-level ways of achieving temporary etherealness (or, failing that, incorporeality) with a low level character (ECL <6)? The best/only options I can find are Permeable Form (LoM), the Shyft race (FF) and Blink (sort of).

The character needs to be corporeal and material most of the time.

[Piggy Knowles]

The earliest possible way that I know of is the Ghost savage progression (http://www.wizards.com/default.asp?x=dnd/sp/20040117a), allowing you to pretty much immediately be incorporeal. But it wouldn't do much for you being corporeal/material most of the time. Maybe look into Ghostwalk for some options on being a ghost that can influence the material.

Alternatively, you could pump all your WBL into purchasing a scroll of Lesser Planar Binding, and bind a Nightmare (http://www.d20srd.org/srd/monsters/nightmare.htm). That would give you Astral Projection and Etherealness at will.