hola maycolalvarez, pues utilizo imagemap, mi codigo es el siguiente:
<form name="hola" action="muestra.php?CONTINENTE=Oceania" method="POST">
<input type="text" name="palabra" value="ma" />
<h4> Busqueda geografica: <h4>
<h6> Seleccione una o varias extensiones: <h6>
<map name="unnamed">
<area shape="poly" title="Oceania" alt="Oceania" nohref onClick="hola.submit()" target="_self" coords="380,210,381,212,381,215,379,219,379,222,37 8,225,375,231,375,234,376,236,376,242,377,244,377, 247,378,249,378,252,380,256,380,262,381,264,381,27 0,382,272,388,272,392,270,395,270,397,269,400,269, 402,268,405,268,413,272,414,275,416,277,418,278,42 0,282,422,284,424,285,426,287,434,291,437,291,439, 292,442,292,444,293,447,293,453,290,456,290,458,28 9,464,277,463,275,461,274,458,273,452,273,450,274, 438,274,436,275,432,273,431,271,431,265,433,261,43 3,258,427,246,427,240,430,234,430,222,429,220,423, 220,421,221,409,215,405,211,402,209,401,206,399,20 2,397,201,391,201,389,200,387,202,383,210,383,213, 382,215" />
<area shape="poly" title="Asia" alt="Asia" href="muestra.php?CONTINENTE=Asia" target="_self" coords="276,94,276,103,274,107,274,110,273,113,273 ,125,276,131,278,133,279,135,279,138,280,140,284,1 42,285,144,287,146,287,149,285,153,287,155,290,161 ,292,162,293,164,291,168,289,169,286,169,284,170,2 81,170,280,172,278,173,276,177,276,180,280,188,282 ,190,288,202,291,202,293,203,299,203,300,201,304,1 99,308,195,309,192,310,190,322,190,323,192,325,193 ,328,199,328,202,330,203,331,206,333,210,335,211,3 38,211,339,209,342,209,358,217,360,219,361,221,363 ,223,365,224,366,226,370,228,371,226,373,224,374,2 22,374,195,376,193,380,191,383,191,385,189,387,188 ,389,184,391,182,397,179,400,179,402,178,405,178,4 15,173,417,171,419,167,419,164,420,162,420,153,419 ,151,420,149,420,146,421,144,421,138,425,136,431,1 36,432,138,434,139,440,139,441,137,445,135,446,133 ,447,129,447,126,449,124,450,122,452,121,455,120,4 58,120,460,119,463,118,464,116,466,115,467,113,467 ,107,468,105,471,102,473,101,474,103,476,104,478,1 03,480,99,476,97,474,93,471,93,468,92,466,90,464,8 9,449,89,446,88,444,87,441,86,431,81,430,79,428,77 ,427,75,427,72,428,70,432,68,430,64,428,63,425,63, 419,61,413,61,409,63,408,66,407,68,405,69,403,71,4 01,72,389,72,383,69,383,66,380,60,380,57,379,55,37 7,54,374,48,372,46,372,43,371,40,369,36,367,34,365 ,30,363,29,362,27,360,26,351,26,346,36,346,39,347, 41,349,42,350,44,352,45,354,49,355,52,357,54,356,5 7,355,59,353,60,352,62,348,64,346,68,344,69,342,71 ,338,73,335,73,331,75,325,75,323,73,321,69,321,66, 323,62,323,59,322,57,320,55,317,55,316,57,310,60,3 09,62,305,64,304,66,302,67,300,69,298,70,295,76,29 3,78,290,80,289,82,283,85,281,87,279,88,278,90,276 ,91,275,93" onClick="return leer();"/>
<area shape="poly" title="Europa" alt="Europa" href="muestra.php?CONTINENTE=Europa" target="_self" coords="222,...../>
<area shape="poly" title="America del Sur" alt="America del Sur" href="muestra.php?CONTINENTE=Sur" target="_self" coords="112,203,114..../>
<area shape="poly" title="Africa" alt="Africa" href="muestra.php?CONTINENTE=Africa" target="_self" coords="222,174,225,174,...../>
<area shape="poly" title="America del Norte" alt="America del Norte" href="muestra.php?CONTINENTE=Norte" target="_self" coords="108,200,110,199,......./>
</map>
<CENTER>
<IMG {border-style: none; src = "mapa-mundi.jpg" usemap = "#unnamed">
</CENTER>
</form>
y mi intencion es enviar la variable continente junto al form, pero de forma dinamica esto es q continente vaya tomando el valor q corresponda a la zona apretada.
mychas gracias x tu interes