Google mobile maps is great. Version 2 was recently released and contains a beta feature called 'My Location'. You might say this isn't so amazing, but what if I told you that this feature does not require any form or global position system (GPS)... interested?
If so, watch the above introductory video about Google mobile maps and its new feature 'My Location'. You can download Google Mobile maps directly from Google. Note that the My Locations also supports GPS.