Is the TV Guide On Screen useful with a set-top box?

"Can I (and if so, how) use the TV Guide On Screen with this setup?"

You can't

Bottom line is if you have any premium HD channels you receive, since your TV has no cablecard slot, you have no choice but to use the STB to receive them so the built in guide on the TV won't be usable.

I'm not so sure Matt...
a) some cable providers do carry TVGoS info on a particular channel.
b) TVGoS is transmitted OTA, typically by a local PBS station, but not the rule.

I'd suggest that the OP hook up an antenna, check the TVGoS setup instructions in the manual and see what he is able to receive. Note: if you are successful finding a TVGoS affiliate, it will take a few hours to fully download the info and will be required to keep the antenna attached for any updates.

Still not going to do much good when you are using the HDMI input on the set and the cable box to tune channels. Sure you could flip over to the tuner in the set to look at the guide then flip back to the HDMI input to watch TV but that would probably get old after awhile.

Just because he can get the data via cable doesn't mean he'll be able to use it for the cable channel lineup. In his case, since he's using a cable box to receive encrypted content via digital cable, TVGoS on the TV itself is completely irrelevant, as it's a separate tuner that isn't being used by the setup he has.

"Assuming as Ratman suggests that I may be able to pick-up the TVGoS info from PBS via Cable, would the following setup work to allow me to enjoy TVGoS without having to switch back and before b/w cable box and tuner?"

I would assume there is no way to view the TVGoS guide data when using any input other then the built in tuner on the TV so I'm going to say no.

TVGoS info provide cable lineups too. Not just OTA.

If believe TVGoS info is "loaded" into the TV a stored/updated on a weekly (or daily?) basis.

As for viewing that info, check your user's guide to verify any input dependencies/restrictions.

If the set uses an IR blaster that will control the box, he could maybe split the signal, one lead to the TV and one to the box (which is hooked to the TV through composite or HDMI), and the TVGOS will download and can be used to program recordings off of the cable box.

I don't know if it can be done with that TV and his service, but that's one possibility, at least for recording.

But yeah, he'll always have to change to the TV input to view the guide. But if he's just watching the locals, then he won't even have to bother switching back to the box, because he'll be getting those in digital HD and SD on the TV's tuner, also.

Of course, they might channel map funny, and be different from the channel numbers he has set in the guide, in order to control the box - so he won't be able to go to the guide and the channel in it and just press "enter" to get there - unless he's getting something on those channel numbers otherwise (for example, the analog or digital 480i versions), and doesn't mind watching those - which, if they're also in HD elsewhere, would be highly unlikely.

Personally I've never seen a set that can remote control a DVR via an IR blaster to schedule recordings. Looking at the jack pack on this set, there is no IR blaster hook up option.

My Pioneer 1140HD plasma with TVGOS can control VCR's with an IR blaster, so I thought it was at least worth investigating.

I think it's pretty rare these days to even find a set with a CableCARD slot in it. At least a recent model.

TiVo or a no-fee Sony DHG-HDD500/250 can accept a CableCARD.

Once "Tru2Way"/OCAP hits later this year, there may be a resurgence in CableCARD-equipped TVs, but yeah, for now, it seems most makers have just decided it's not worth it - too trouble-prone, requires too much interaction to set up, no SDV, etc.