It's hard to see how not signing up for cryonics could be "conspicuous" (except for a small minority of professional transhumanists who might face questioning about it, like Eliezer) since (1) to an excellent first approximation no one has signed up for cryonics, so the signal gives rather little information, and (2) it's only going to become public if you are close to death (or if you put out a press release about it like Paris Hilton, I guess).
To most people, abstaining from other luxury goods in favour of cryonics is going to look and feel much more like self-sacrifice than abstaining from cryonics in favour of other luxury goods. In fact, it's probably only among (a certain sort of) high-calibre rationalists that Nick's conjecture would have any plausibility.
...on signing up for cryopreservation with the Cryonics Institute.
(No, it's not a joke.)
Anyone not signed up for cryonics has now lost the right to make fun of Paris Hilton,
because no matter what else she does wrong, and what else you do right,
all of it together can't outweigh the life consequences of that one little decision.
Congratulations, Paris. I look forward to meeting you someday.
Addendum: On Nov 28 '07, Paris Hilton denied being signed up for cryonics. Oh well.