It's the time of year for new spring fashions. Personal digital assistants are no exception, so Palm Inc. is adding a splash of color, while Handspring Inc. is touting "thin is in.

Palm has introduced two PDAs: the black-and-white m500 and the color m505. Palm has added to both versions the Secure Digital expansion card slot, which supports add-ons and peripherals such as infrared printers and voice recorders.

"If you look at all the digital products out there, it's a very disjointed world," says David Christopher, a product marketing director for Palm. "What we envision is an environment of collaboration and sharing of data and photos, audio files, enterprise data, etc., using a Palm device."

The m500 and m505 also will have Secure Digital input/output capabilities that will eventually enable third-party companies to provide devices that interact with the Palm.

Handspring last week unveiled its Visor Edge, a thinner version of its Visor product line, in a direct attempt to compete with the trim Palm V device. Handspring has long provided an expansion slot for third-party hardware modules, including additional memory, cameras, and phone adapters.

The potential similarity between the Handspring Springboard and Palm's Secure Digital Connector may create what some analysts are calling "slot wars." "You have all these different slots, and in four or five years, one or two slots will become predominant," says Gerry Purdy, CEO of MobileInsights, a market research firm. "Regarding SD, I think smaller is always going to win out. In the future, Springboard with its large PCIA board isn't going to work--it's just too big. Springboard will be around for a long time, but it will eventually give way to a smaller form factor."

The new PDAs will also support USB connections and will include the latest Palm OS 4.0 with support for the expansion slot removable media. The Palm m500 will be available in the last week for April and will be priced at $399. The m505 will be available the first week of May and will be priced at $449. The Handspring Visor Edge is available now and is priced at $399.