"Se il tempo si permette vogliamo mangiare fuori."

I should have said "vorremo" and not "vogliamo" - would like rather than want.

I think Franco's "preferiremmo" is a bit weak.

Regarding emails the problem is that many restaurants set up a website to advertise themselves but not all actively follow up the site or their emails. A good clue is to see how recent are the menus, news etc.

A good tip to solicit a reply is to send a text message (if a mobile/cellular number is given) saying simply - "Ho mandato un email"

You can tell if the number is a mobile/cellular by checking if there is a 0 at the beginning. Excluding the 00 39 or +39 (being the code for Italy) all fixed line numbers in Italy then begin with a zero. If the number is not a zero but a 3 then it is a mobile/cellular number.

nochblad, please... don't insist. Try googling "se il tempo si permette" - there's just one result over the whole www: this thread. That phrase is meaningless. Of course, you can, in my sentence, say vorremmo (double m!) instead of preferiremmo, if you prefer; however, it's still less polite than "preferire". (The weaker the politer, so to speak.) Or you can say "il tempo permettendo, vorremmo/preferiremmo..."
And sending a text message to alert them of an email is certainly an interesting idea, though you could send the reservation request proper by text message, as well. But please note it's "una email", not "un".

I am reading and learning during this lesson in Italian etiquette, grazie a Franco.

"Email" in Italian is electronic mail, the whole system. A single email message is "una mail".

I would not send anybody a text message telling them to look at the e-mail I sent them regarding a restaurant reservation unless they worked for me as my personal secretary! In any culture!

This is only partly correct, Zerlina, sorry. Italian "email" (or actually, "e-mail", much more frequently) may mean the whole system OR the single message (OR also the email address); while you CAN shorten it to "mail" when speaking of the single message, which is however not that usual.
Cf. Treccani, the bible of the Italian language: http://www.treccani.it/Portale/eleme..._E_037863.xml; or else, for example, http://www.mestierediscrivere.com/in...articolo/email.
Additionally, try googling (results in Italian only): "una e-mail" 10.100.000 results, "una email" 976.000 results, "una mail" 3.150.000 results.
Also note that "una e-mail" seems actually unusual since with other words, "una" would be shortened to "un'e-mail", while for this particular word, "una e-mail" is being used much more regularly than "un'e-mail". "Un'email" 978.000 results on Google, "un'e-mail" 3.470.000.

The Treccani link above doesn't work. New try: http://www.treccani.it/Portale/eleme...I_E_037863.xml

I forgot to say, "mi piacerebbe...." works well for me.

Actually, yes, that's an excellent alternative possibility, come no! Ci piacerebbe mangiare all'aria aperta. Literally, it would be a pleasure for us to eat outside. Very polite, thus.

I am enjoying all this exchange enormously. Many thanks everyone for contributing. I agree with those who say that it is nice to just stroll around and find somewhere you like the look of and also that many of the best places won't have fancy websites. I had thought I would book for the first night so that we are guaranteed a straightforward and hassle free start to holiday as we will arrive on a saturday evening which I guess might be busy. My eye was drawn to Ristorante Maccheroni, which looks from reviews to balance touristy with local interest. I am also now v. keen to visit the e-mail free Osteria dell'Angelo so will have to learn some Italian before we go!

Very good plan, loncall, particularly for a Saturday. You may be interested in reading this thread http://www.fodors.com/community/euro...estaurants.cfm, where you'll find many more restaurants (obviously, you're going to Rome!) and where I discussed the problems of weekend dining towards the end of that long thread.

Just to complete this little "Italian lesson", I might add that permettersi means "to dare", hence "se il tempo si permette" "if the weather is daring", more or less. :)