Few things are as elemental to travel as guidebooks. Whether for a weekend in Washington or three months of exploring Australia, Fodor's, Frommer's, Lonely Planet and Moon tell us what to see and where to eat.

But all that weight and bulk can become a nuisance.

Fortunately, 2012 is shaping up as the year when travel guidebooks make a big leap into the electronic realm.

Frommer's recently started releasing e-books that also are accessible as smartphone apps, including electronic versions of Alaska, California, Costa Rica, France, Great Britain, Japan and Spain guides. At $9.99, they're cheaper than the paper versions, lighter, fit in your pocket and contain all the same information. They also have map and photo features.

It also has been a big year or so for Lonely Planet. The world's largest manufacturer of travel guides has matched all its paper books with e-book versions -- both new and old -- which it will continue to do.

In April it launched an app series of country guides ($9.99 each), that are condensed versions of those thousand-page books but add features based on a device's functionality. So far it has released guides to Australia, Costa Rica, England, France, Ireland, Italy and Spain in app form. In June, Lonely Planet also launched regional guides in app form, such as "Florence & Tuscany."

Lonely Planet has been in the business of city guide apps for three years, but whittling the country guides to sizes that wouldn't dominate a device's memory took time, said Jeremy Kreitler, Lonely Planet's vice president of mobile technology. Most of the country guides are between 200 and 400 megabytes -- large but hardly unwieldy on a 32-gigabyte phone.

On the road, the maps offered by guidebooks offer clear upgrades to what's in paper form. Travelers can zoom in and out of the maps, find locations relative to where they want to be, and use links to make phone calls.

Lonely Planet plans eventually to have corresponding apps for every guidebook it publishes and to be able to bundle apps with sales of paper and e-books; Kreitler said neither the iTunes music store nor Google's online Play story now allow for such bundling.

Though Lonely Planet's country apps are not quite replacements when planning trips -- books remain more thorough and easier to browse -- on the road, apps are ideal. As important, the information is stored on the device, meaning a Wi-Fi connection or cell signal is not necessary for access.