Day trip from Florence

Venice is too far. You could do a day trip to Pisa/Lucca. There's not much to Pisa outside the tower, baptistery and duomo. You only need a couple of hours.

Look into taking a day trip to a Tuscan winery. Do a food and wine tasting for lunch.

Personally, I'd choose one or the other. There's so much to do and see in Florence. A week will hardly scratch the surface.

Pisa is a 1 hr train ride from Florence. You can easily combine it with Lucca, which has regular connections with both Pisa and Florence. Use the website of the Italian railways for the connections. (Fill out »Firenze S.M.N.« for the main station in Florence.)

Forgot:
Another wortwhile day trip is to Siena. Best done by bus. They leave frequently from the bus station across the road from Florence main railway station.

We did a day trip from Florence to Venice several years ago and, although it was indeed a long day, it's eminently doable if you get an early start. The trip takes about 2 hours each way and the trains are comfortable, efficient and (relatively) quick.
If you're so ambivalent about Pisa why not just skip it? There are other, more interesting day trips to be had, including Siena, Lucca, and our personal favorite Fiesole located in the foothills above Florence. You can get there via a short bus ride from the city.

Robert makes an excellent point! There's really no need to go to Pisa just because "it seems like something" that one should do. You may very well find Lucca and Siena far more interesting, both deserve a day, and they are just as easily reached by public transit. As he also mentioned, Fiesole is even closer and doesn't take long at all to get to by local bus.

I probably would save Venice for another time, though. It's been years since I've last been but the word on the RS "street" is that it's much more enjoyable these days if you're there during some of the hours that the hordes of day-trippers are not...which is evenings and early mornings so at least a couple-night stay is usually recommended. It would be nice to have enough time to explore some of the islands, too?

I vote for Siena and Lucca!! Not both, just chose one or do two day trips and see both. Love them both and certainly skip Pisa!

I probably would save Venice for another time, though. It's been years since I've last been but the word on the RS "street" is that it's much more enjoyable these days if you're there during some of the hours that the hordes of day-trippers are not...which is evenings and early mornings so at least a couple-night stay is usually recommended. It would be nice to have enough time to explore some of the islands, too?

Kathy makes a good point. Before burning a day away from Florence and going to Venice, read this and decide:

Venice and cruise ships

The others make a very good point about the daytime crowds in Venice. Though our day trip was years ago, I do recall the crush of people in and around St. Mark's which made moving around such an ordeal. Better to schedule at least one overnight in the city so you can enjoy it after the "boat people" return to their ships...or early in the morning when the place is truly magical.

We took our first trip to Italy in October and we didn't follow the 'what we should do' ideas, but followed our hearts on what we wanted to do our first time there. We flew into Pisa and took the train through on our way back to Florence, but never stopped there. We followed what interested us and are very happy we did. Follow your heart! And this forum was invaluable for gathering information and ideas on our trip to make it unforgettable.

Lucca is a laid back town. You can walk or bike ride around the town's walls. Very relaxing, like going to a park. Pisa, you go, look at the tower, and leave.

Siena is amazing, short bus ride (1/2 hour) from Florence. More lively (and touristy, at times) but great to explore and hang out in Il Campo for food, drinks, and people watching.

Both are historic towns with so much to see, depends on your preferences. I personally have spent a few nights in each.

Siena is amazing, short bus ride (1/2 hour) from Florence.

I think you left out the 1 or the 2. The shortest time I see is 1 1/2 hours. Some were listed at 2:20.

It is still not that long and Siena is wonderful!

Pisa is a lovely city, but I almost never recommend it as a daytrip unless it's combined with Lucca. You could spend most of the day in Lucca and get to Pisa in mid- or late afternoon, when the crowds are thinning and the vendors are closing down, but especially when the golden light hits the white marble structures. Make time to walk through the cemetery (Campo Santo).

Thank you to everyone - this helps.