After the second day (my first) of the action-packed TechCrunch50 show, here are a few of the newly launched companies I got to talk to, and the reasons I liked them. To stay true to the show’s title, I’ll keep it to multiples of five (or more accurately, just five). Some involve local search, some mobile, and some are just plain cool. Check ’em out:

Fitbit

This company has little to do with local at the onset but could as its product and ad model develops. Breaking away from being solely an online product, Fitbit employs a small wireless device that attaches to clothing and uses an accelerometer (like the iPhone) to measure myriad daily behaviors related to your health. These include steps taken, miles traveled, hours slept, etc. It then crunches, aggregates and organizes all those data to tell you things you want to know about your health (and things you never thought to ask).

The Good: This information is wirelessly uploaded whenever the small device is near the base station. This is then shared with the Web site where a personal health portal spits out the data in various mashups. Social elements come into play in sharing with others and starting groups for various health causes (think walking group or marathon training groups).

The Bad: The addition of proprietary hardware that is necessary for the product to function could be an adoption barrier in the multi-device world in which we live. Ad sales will be needed for the online portal, which comes with its own set of challenges — short of joining an ad network and sharing contextual ad revenues.

Swype

This company has built an underlying technology that makes data input easier and more intuitive on smartphones. This comes at a good time, when devices and mobile interfaces themselves are getting easier and more intuitive. Using a finger (touch screen) or a stylus (stylus-based devices), users start with a letter then swipe across the keypad, stopping on each letter of a word. Words then appear on the screen, including predictive text for unknown or misspelled words. Although it may sound complicated, many TechCrunch50 judges tried it for the first time onstage and showed that it can be picked up easily.

The Good: After a few weeks the company claims it’s easy to input up to 50 words per minute. Along with the device standards that have made a quickly developing set of applications more feasible and marketable, more efficient data input could complete the circle and further this cause.

The Bad: The technology is based on (limited to) touch-screen devices. This means it essentially banks on the fact that the touch screen will be a longstanding and pervasive standard across the screen-based devices that permeate our lives. This may be a lot to bet on, as it has been only a year since the iPhone started getting everyone excited about touch screens. Its second challenge will come in its business model. To get this product to market, it has to work with original equipment manufacturers, which are under tight control of the famously stringent (though loosening) mobile carriers. There are only so many it can work with, which is a double-edged sword.

Tonchidot

This company falls into the nascent category (at least in the U.S.) of mobile visual search. The Japanese company feeds location-based data to iPhones, which are displayed in the phone’s camera mode when held up against a cityscape. In other words, the display shows a number of icons floating in the air that are relevant to that location and to users’ predefined interests.

The Good: Icons can be filtered by category (“air filter”) and clicked to drill down into business details. Further drill-downs can be used inside stores to find out specific product info and also tag notes to share with friends.

The Bad: It’s a nice idea and a compelling demo (you kind of have to see it), but like everything else in local, accurate and comprehensive data will be the challenge to making it work — especially at the level of robust data we’re talking about here. And the use case is purported to shine in urban areas and inside stores — precisely the places where GPS falters.

Gazaro

This company joins the small but growing pack of companies focusing on local product search. This segment is growing with the realization that most retail activity takes place offline in physical stores. Leading and tracking those transactions becomes the product strategy.

The Good: Like others that have entered this space (ShopLocal, Krillion, Slifter), it is focusing first on electronics — a category with higher likelihood of the need to see a product before buying, and avoid shipping costs. It gets its data by scraping retail and manufacturer sites for both product information and availability.

The Bad: It doesn’t yet have real-time product inventory information like Krillion and NearbyNow, except for the information provided by some retailers. But this usually involves a binary “in stock” or “out of stock.” More features to reserve online and get pricing promotions will be the key to compete with the above players and more effectively track purchases and integrate transactional ad models.

Adgregate Markets

This company joins a small but progressive crop working on more functional and media-rich display ads. More specifically, it’s making them more actionable and trackable by integrating e-commerce capability right into the ads. This includes audio excerpts for things such as books that can then be purchased on the spot. The company has already signed a number of online book sellers and publishers such as Random House.

The Good: Trackable ads bring more transparency to advertisers by going beyond the click to actual conversions. The company’s “ShopAds” have also been widgetized so online publishers can plant them on their sites, thus gaining transactional capability without any back-end development or investment.

The Bad: Market opportunity could be limited to product categories that are conducive to e-commerce (books, movies, commodities, etc.). Low-margin items could require the company gain more scale.

More to come from Day 3 of the show. Stay tuned.