The N82 is pretty bloody good - I use the sports tracker, and have used maps when I've taken a wrong turn.
It's only the live sharing and turn by turn navigation that's chargeable, so you can set it up to not do anything that uses your data allowance up quite easily. The downside, of course, is that as a phone, it's not ruggedised or waterproofed in anyway, although there are after market solutions available for this.