Stefano Garuti

This plugin allows you to directly embed Gmaps code in your posts or pages using the [gmap] shortcode.
HOW TO USE IT: 
When you are in the Write Post or Write Page screen, find the “Custom Fields” area. 
If isn’t already there, add a custom field named exactly “gmap” (without quotes) and copy and paste 
in the value field the whole code you obtained from Google Maps. 
Write anywhere in your post or page the “shortcode” [gmap]: when displayed on the blog it will be 
repalced with your Google Map. 
Save and publish. You are done!
UPDATE and NEWS at: http://www.wpmania.it/google-maps-mania-plugin/

GmapsMania

This plugin allows you to directly embed Gmaps code in your posts or pages using the [gmap] shortcode.

Cláudio Esperança

This plugin allows the integration of Google Maps on your pages or posts using the WordPress Editor (TinyMCE). It supports multiple maps on the same post/page and within each map you can set many options, like the position of the marker, controls, icon of the marker, InfoWindow with Tabs with HTML support, etc. Give it a try.

WP_GMaps2

This plugin allows an easy integration of Google Maps on your pages or posts.

GmapsMania vs WP_GMaps2