Handspring has long offered fast USB synchronisation and Springboard expansion, two distinct advantages over Palm's own model line of PDAs. With the m505 and the m500 (m500 is the mono version) Palm has hit back, with both models featuring USB synchronization and an expansion slot and the latest Palm v4 OS.

The m505 sports the sleek look of its Palm Vx predecessor, but weighs just a bit more; 139g compared with the Vx's 114g. It uses Motorola's 33MHz Dragonball VZ processor, together with 8MB of static RAM memory and 4MB of Flash ROM.

Expansion is the m505's key new feature. Housed in its top edge there's a dual-purpose slot that accommodates SD (Secure Digital) or MMC (MultiMedia Card) modules, and it also features Palm's new Universal Connector, which is located on the unit's bottom edge.

The m505's screen retains the 160 x 160 pixels resolution as ever, but is a 16-bit, 65,536-colour, reflective side-lit display. Unfortunately there's no adjustment to the brightness, so indoors the screen is a little dimmer than either the iPAQ or the Palm IIIc. But where the m505 scores is when it's used in sunlight; the screen is just as viewable as the iPAQ, making it the first Palm screen that is truly usable in daylight.

Although not the perfect device to use the Palm OS, the m505 brings Palm back into the PDA race with the one of its best own-brand units to date.