Have no source for you but Overseer from Dafont is close -

http://www.dafont.com/search.php?q=overseer&text=SPICE&psize=l

Here's the specimen in question. It's definitely in the same vein. Dan X. Solo's books were nearly comprehensive, he just wasn't great about providing source information.

[duplicate of post below; deleted by author]

Thank you so much, ralphsmouse! I sincerely appreciate it. Yes, I see now that it is similar, but not an exact match. Sigh.
I know the typeface I'm looking for is not custom because I've seen it used a few times over the years on a wide range of things. For example, the logo of the French charity AIDES and a video cassette titled Secretos de la Trilogia de Regreso al Futuro, which I assume is a documentary about the Back to the Future films.
The latter item tells me that the typeface has been in use since at least 1990. Gosh, I wish I could figure this out!

I'm thinking this typeface could be from a dormant/defunct early digital type foundry. From what I can tell, Spice Girls fans have been trying to figure out the origin of this particular typeface for ages. For that reason, I can't be sure if the typeface was ever widely known or distributed. It might have came on a type CD-ROM package (a very 90's way of distributing digital typefaces).

My apologies by advance if my words sound lazy/boring/dull/killjoy because everything I'm going to say has already been said and argued. But since it's stumped all type ID communities across the world, maybe it is time to definitely close and accept the evidence... SPICE GIRLS will never return and even if we identify the font.
To me, from what I could see from this CD covers is they're at least 2 different fonts (or 1 font and 1 lettering). /S from 'SPICE' woodmark has a horizontal transition not the one for text.
The text one looks like Europa Grotesque (less is California Grotesk mainly because of /a spur). That said it could be not so hazardous to accept the idea 'SPICE' would be a custom lettering, derived from Europa Grotesk (and very easy to recreate actually).

Ryuk, I feel what you say, but for me the |S|s on the CD are too small to determine which type of curve they have on the spine, and the ones on the MiniDisk (http://lonestarspice.com/albums/spicemd2.jpg) have the same angle as the one on the logo. And the new examples given by Rick (http://typophile.com/node/119444#comment-588084) also have the same kind of |S|.

Definitely Europa Grotesque/California Grotesk-inspired. Here's some more.

Riccardo, you may be right (I'm getting old ;) but your words do not help the cause... Let the SPICE GIRLS rest in peace and accept the ineluctable truth. There will be no come back for them! But I agree, I'm probably as bitter as you... No more Posh, Sporty, Ginger, Baby and Scary all together... I know but we're living in a cruel world... And it does not solve the mystery either... And what about Europa Grotesk with a custom /S to end up the discussion?

Haha! Thanks for the laugh, Ryuk. Yeah, I'll admit it (although I'm pretty sure it's painfully obvious): I'm a Spice Girls fan, have been since I was 13, and yeah, the Spice Girls are definitely not coming back. I'm happy with the fact that they're done, actually; their new material on their Greatest Hits release proved that they're no longer the success that they were back in the late '90s. (Just between us: the new songs were AWFUL. There, I've said it!)
Thank you again for your contributions, ralphsmouse. Appreciated. I, too, have wondered about it being some obscure early digital type, the product of a long-defunct foundry, or simply a face that was offered for a time and then taken off the market (it's downright painful when that happens!).
The closest I've come across is House Gothic -- particularly its Bold Alternate Caps -- by House Industries; the 'S' is remarkably similar -- the other letters ... eh, not quite.
Oh, and thank you too for your input, Riccardo. I love being around knowledgeable type peeps.

Just for the sake of completeness, and to corroborate what Rob (ralphsmouse) and Ryuk suggested, I will add that, according to MyFonts, the digital Europa Grotesque (2002?) is "based on [ATF's] Europa Grotesque series circa 1960".
So there could have been an early (more or less legit) digitalisation of it, and maybe the horizontal spine of |S| was in the original (or, au contraire, was introduced to get away with the knock-off).
Unfortunately, I'm unable to locate a pre-digital specimen (or any mention of it, for that matter: http://en.wikipedia.org/wiki/American_Type_Founders_%28list_of_types%29 ).

Full disclosure: I never had willingly (or knowingly) listen anything by the Spice Girls.

The Europa Grotesque connection makes sense, guys. Thank you.
To me the "Spice Girls font" seems softer and (dare I say) rounder than Europa Grotesque -- at least the digitalization(s) I've seen. Even so, it doesn't rule out the possibility that it might be derived from Europa Grotesque.
I'm now at the point where I'm considering contacting AIDES to inquire about who designed their logo. Does that make me seem crazy, obsessed and ever so slightly desperate?

yes.

Then crazy, obsessive and desperate I am! :)

et tu, Donte?

I always loved this font, i never found it. So i re-create it for one of my project. It was hard, but it's ready. :) (Sorry for the "sample" watermark, but...)