Like the topic says;

I'm about to purchase some running gear for my fixie project. Pretty much all previous bottom brackets I have dealt with upto now have been Shimano, and thus that's what my tools are. I haven't seen anything to the contrary - but will the same tools for the Shimano square taper brackets handle the Sugino 103mm units? They look mighty similar from the photos on Sheldon's Harris Cyclery pages.

tah muchly...

I hope so, I just put a Sugino VP crank on a Shimano square taper BB. I use the same tools for both.

Yeah, even the new Campy stuff uses a Shimano interface. It seems pretty universal now.

Thanks guys, it's looking positive.....

but just to clarify; I meant the tool/socket attachment for mounting the b/b cartidge into the shell - as opposed to the tool for pulling cranks off the crank spline.

I specified square taper, just to distinguish the Shimano from their Octalink series splines. I know they use a different cartidge tool again. Apologies for my ambiguousessness...

keep on treadlin'

All square taper is the same.

Not all square-taper is the same, based on the question that you're asking.
First, there are two square-taper standards, ISO (Campy and Stronglight, and - randomly - Sugino 75's) and JIS (Japanese and most others). The ISO taper is slightly smaller, although they share the same taper angle.
This does not mean that tools need to be different.

Tools for removing square-taper cranks from the bottom bracket are all practically the same - doesn't matter brand or taper standard.

But as to your question: tools to install or remove the BB into the frame's BB shell do differ by brand and often within brands, especially with cartridge BB's. However, Shimano and Sugino's cartridge BB's have the same interface, as does Tange and plenty of others.
It may be that the Shimano interface is totally common now, as seely says. I've got a Campy sealed-cartridge BB from 2000 (Mirage 9-speed triple gruppo) and it's got a completely different interface, takes a different wrench.

Campy sealed bottom brackets take a specific installation/removal tool (Park's BBT-5 or equivalent) and are not compatible with the Shimano, et. al. tool (Park BBT-2).

One saving grace is that the Campy bb tool is also the lockring tool for their cassettes so it does double duty.

Incidentally, the Shimano freewheel-removal tool has exactly the same splines as Campy cassette tool and works on Campy cassettes. Do you know if it also works on newer Campy square-taper BB's?

No. Campagnolo uses a slightly different square taper.

I think that Tange makes the cartridge bottom brackets for both Sugino and Shimano.