Haven't done a surround mix in a long while But now I have a few commercials to mix in surround. They are mostly conversational, so not very interesting sonically. I haven't gotten the OMF files yet, but I am wondering how you deal with this? Keep the dialog in the center or spread it out a little between LCR. Add some reverb to the LS/RS and call it a day? Would like to do something more interesting, but don't seem to have a lot of options.

There are a couple of options.
1 - Keep all dialogue to Centre channel, SFX to all 4 corners and music to LR.
2 - Set the dialogue to L-C and C-R as this allows a more accurate placement of the voices - especially useful if there are 2 speakers onscreen at the same time.

I would keep vocal FX where they sound most natural - and certainly not just reverb to Ls/Rs, but including this in L/R as well.
Do you have to do a DigiBeta export to Main plus M&E or just the main to DigiBeta?
What are the delivery requirements - odds are very high you'll need to run a Matrix Stereo as well, using Dolby ProLogic II for preference, as DPL II decoders will emulate LCRS/DPL etc as well as full DPL II.
The agent may also want a discrete split version too.
Finally, just to make it really interesting, some folks still insist on DA88 - as I have just found out.

Hi Neil, thanks for the tips. I think I was trying to make something out of nothing. Even though the spec (D5) allows for surround, no need to have SFX swirling all around you. The only part I had trouble deciding on was a section where two people are walking down the hall while loud rock music plays from another room. It would make sense to have the music in the center as well, but for the sake of the dialog clarity, I did not put it in. Because the client insisted on changes up the the very last minute, we ended up remixing everything at another studio for the bargain price of only $1,000 USD per hour

Making something out of nothing is what we all do, I reckon!
Lost count of the last minute rescue jobs we have had to do.

There is indeed usually no need for the SFX to swirl around - this can work with music mixes, but in film work the brief is often (unless it's a strange movie) to make the mix as natural sounding as possible. Simple is often best at mixdown.

The section you mention - I would put the rock music on it's own track, filter it to make it sound as if it is in a different room, and feed it to wherever makes sense with the action - and I would also have left centre channel clear for dialogue, as when you do the Lt/Rt mixes (Main plus M&E) having stuff panning all over the place could collapse the soundfield.
Having just said that, the situation may have been better with the music in all 3 front channels as well, possibly ducking the music in centre channel when someone is speaking?

Hi Neil, I ended up putting only the dialog in the center channel. Even if it wasn't totally realistic, the dialog came through a lot more clearly. I just remember Fredo commenting that this was how Studio 54 was mixed and it wasn't completely convincing with the (source) music only coming out of the L & R.

It's usually for the best to keep dialogue in the centre.
Although having said that, therre is definitely an argument for working with dialogue by creating it's own 5.1 group.
Then you can pan dialogue, so where you have a scene with 2 characters sitting side-by-side (a favourite shot in widescreen film) yopu can have the one on view left panned to Left of Centre, and the other to right of centre.
It must be subtle though, and not L/R panned, or things will be dreadfully un-natural.
Batman Begins does this to some extent, and it can work really well. It's also dependant on the recording chap doing his job properly, as you'll need each Lav mic on it's own track, for each character, as well as the boom.
If the dialogue editor has cut it all onto a single track you're also in trouble that way too.

Surround is wonderful - the main rule is "There are no rules".
As usual, if it sounds right.......