When GPS units became mass-market items, I relegated mine to my ex-gadgets page.

However, the Zumo 550 is sufficiently clever to qualify for the gadget label as it does four jobs in one:
- Navigation
- Speed camera alerts
- Traffic alerts (with auto re-routing)
- Bluetooth handsfree phone

While TomTom has captured a large slice of the market, I still strongly favour Garmin.

The main reason is that the routing is much more efficient - TomTom takes some very strange routes indeed for some journeys! Indeed, on some routes it does three sides of a square. In contrast, Garmin's in-GPS routing is excellent, as is the supplied MapSource software if you prefer to do your routing in advance on a PC and then upload to the GPS.

For ordinary GPS navigation, the Zumo 550 is the latest generation. This means that it has the whole of Europe at street-level (version 9) built-in, supports whole postcodes, has a high-sensitivity antenna (so holds the lock when surrounded by tall buildings) and announces roads by name (eg. "Take first exit onto Regent Street").

For speed camera use, £19/year buys you a subscription to the excellent PocketGPSWorld database, which has both fixed cameras and mobile sites. Do not under any circumstances waste your money on the Garmin camera database: it is highly inaccurate and the updater very often doesn't. I had to push Garmin very hard to get a refund, and that refund took four months. (In fairness, this was very much an exception to my prior and subsequent experience of their customer service.)

The PocketGPSWorld instructions aren't very clear. What you need to do is download the UK Speedzoned database, followed by the European Speedzoned database. Unzip both, and copy the entire contents of the both folders into a new one - saying 'yes' to overwriting duplicated files (this is just the licence, etc). Then use Garmin's POI loader to upload that folder. This is because the loader starts by erasing any existing stored POIs, so you always need to put all the ones you want into a single folder.

Adding a GTM21 traffic antenna gets you a lifetime subscription to Trafficmaster. You then get traffic alerts exactly as per a separate Trafficmaster box (green for 20-25mph, yellow for 10-15mph, red for 0-5mph):

But because the traffic info is integrated with the navigation, it is even better. If there is a holdup on your route, the Zumo displays a warning triangle on the main navigation screen with a number inside it - the number tells you how many minutes the delay adds to your journey. That delay is included in the ETA, and the congested stretch is shown on the map:

If the traffic makes another route quicker, the Zumo will automatically divert you. If it's quicker to stay on the original route despite the traffic, you can still choose to route around it if you wish. Touching the triangle symbol brings up details of the delay and offers an Avoid button. I hate sitting in traffic, so tend to use the Avoid function even if it adds a bit of time.

Finally, pairing it with your Bluetooth phone means that you get handsfree phone functionality on the same device. The phone function uses Parrot software, so you get all the advanced functions: caller display on the screen, voice-activated dialling, access to your phone's phonebook, etc.

The pair (Zumo 550 and GTM21) has an RRP of over £700, but I got both on ebay for £525. Still not cheap, but cheaper than buying four separate boxes, and very much neater.