Here is a Google Maps API static map example, generated from arbitrary data.
A linear path following Broad Street north from City Hall in Philadelphia, PA (USA) was used, but the points could have been taken from .csv data files etc. The points on this map were colored according to their position along the path — but each can be arbitrarily colored from the entire RRGGBB colorspace.
Given its ease of use, lack of cost, and incorporation of road, terrain, or satellite imagery, it looks like a very useful tool for scientific visualization.
The Google Maps API explanation for static maps can be found here.
Here is the HTML code which produced the above map.
(It is shown split into lines for readability, but I found that this seems to break the map API.
When using the API, combine everything into one long line.)
<img src=”http://maps.google.com/maps/api/staticmap?
sensor=false
&size=640×640
&markers=color:0x0000FF|39.953,-75.1633
&markers=color:0x0005F9|39.954,-75.1631
&markers=color:0x000AF4|39.955,-75.1629
&markers=color:0x000FEF|39.956,-75.1627
&markers=color:0x0014EA|39.957,-75.1624
&markers=color:0x0019E5|39.958,-75.1622
&markers=color:0x001EE0|39.959,-75.162
&markers=color:0x0023DB|39.96,-75.1618
&markers=color:0x0028D6|39.961,-75.1616
&markers=color:0x002DD1|39.962,-75.1614
&markers=color:0x0033CC|39.963,-75.1611
&markers=color:0x0038C6|39.964,-75.1609
&markers=color:0x003DC1|39.965,-75.1607
&markers=color:0x0042BC|39.966,-75.1605
&markers=color:0x0047B7|39.967,-75.1603
&markers=color:0x004CB2|39.968,-75.1601
&markers=color:0x0051AD|39.969,-75.1599
&markers=color:0x0056A8|39.97,-75.1596
&markers=color:0x005BA3|39.971,-75.1594
&markers=color:0x00609E|39.972,-75.1592
&markers=color:0x006699|39.973,-75.159
&markers=color:0x006B93|39.974,-75.1588
&markers=color:0x00708E|39.975,-75.1586
&markers=color:0x007589|39.976,-75.1584
&markers=color:0x007A84|39.977,-75.1581
&markers=color:0x007F7F|39.978,-75.1579
&markers=color:0x00847A|39.979,-75.1577
&markers=color:0x008975|39.98,-75.1575
&markers=color:0x008E70|39.981,-75.1573
&markers=color:0x00936B|39.982,-75.1571
&markers=color:0x009966|39.983,-75.1568
&markers=color:0x009E60|39.984,-75.1566
&markers=color:0x00A35B|39.985,-75.1564
&markers=color:0x00A856|39.986,-75.1562
&markers=color:0x00AD51|39.987,-75.156
&markers=color:0x00B24C|39.988,-75.1558
&markers=color:0x00B747|39.989,-75.1556
&markers=color:0x00BC42|39.99,-75.1553
&markers=color:0x00C13D|39.991,-75.1551
&markers=color:0x00C638|39.992,-75.1549
&markers=color:0x00CC33|39.993,-75.1547
&markers=color:0x00D12D|39.994,-75.1545
&markers=color:0x00D628|39.995,-75.1543
&markers=color:0x00DB23|39.996,-75.1541
&markers=color:0x00E01E|39.997,-75.1538
&markers=color:0x00E519|39.998,-75.1536
&markers=color:0x00EA14|39.999,-75.1534
&markers=color:0x00EF0F|40,-75.1532
&markers=color:0x00F40A|40.001,-75.153
&markers=color:0x00F905|40.002,-75.1528
&markers=color:0x00FF00|40.003,-75.1525>
