Well, it is 'doable'. You have seven destinations (although Croatia is a whole country, the others you list are cities - well the AC is a region). So if you did 3 days each and have an entire month that gives you a day for transportation between each. And that is a necessity. Three days in each location with a day to allow for transport between them is a minimum but it will give you a taste.

But your locations are pretty far apart so how were you thinking of traveling between them? The three in Italy you can easily do by train. You could fly into Venice, spend 3 days, train to Rome for 3 more days, then train to Sorrento for three days on the AC. Then you need to get to an airport - either Naples or Rome to fly to your next destination. Check easyjet and 'whichbudget' sites to see where you can fly between. A couple years ago we flew from Rome to Dubrovnik with easyjet for 14€ - but that requires booking many months in advance.

Then you would need to fly again up to the region of Budapest, Vienna and Prague - you can fly to whichever has the best connections and train between them.

As much as I loved Croatia, I might suggest you skip Croatia as it's the geographic outlier. Then you'd have about four days in each locations, a much better time to get to see the highlights.

Does the $5000 include airfare to Europe?

This is a lot to do in a month. We did your itinerary in 2 months (substituting Cinque Terre for Amalfi). In May you could leave your plans loose though, and adjust your itinerary as you go. Have you written out an itinerary, including travel times?

Where did you want to go in Croatia? How were you planning to get from Amalfi to Croatia? That could take some expense and time.

What if you flipped your cities, starting in Central Europe (Vienna or Prague), working your way down to Italy (maybe skipping Amalfi for now), taking the bus to Croatia from Venice, working your way down the Croatian coast then flying out of Dubrovnik?

$5,000 *may* be sufficient depending on transport (air/trains/buses), but Italy is expensive. You'll have to be thrifty.

Isabel's whichbudget is a good site. Sometimes it's better to fly; sometimes it's better to take the train or bus - overnight means you're tired the next day but you also didn't need to spend money on a hotel. We did that several times.

Let's Go Europe is still the Bible of backpackers for good reason IMO - great rundowns of low-cost hostels, hotels, etc plus a wealth of great info for anyone on a budget.

As for trains check out these IMO superb sites for planning a European rail trip - www.ricksteves.com; www.budgeteuropetravel.com and www.seat61.com.

5 grand for a month not including air fare is very very easily done - if you can go in off season expenses can be dramatically lower - not only on air fare but hostels and budget hotels are more readily available. May - Sept, Oct are perfect times for non-peak season travels in Europe.

The Thorn Tree forum at www.lonelyplanet.com

If you are under 26 look at the bargain Eurail Yoothpasses only for folks under age 26.