Para tu blog: Efecto Nieve

Para tener este Efecto primero deben ir a:

Luego copian esto:

Diseño >> Elementos de Pagina >> Añadir un gadget Htlm/javascript 

Luego copian esto: 

<script type="text/javascript"> 

/****************************************** 

* Snow Effect Script- By Altan d.o.o. (http://www.altan.hr/snow/index.html) 

* Visit Dynamic Drive DHTML code library (http://www.dynamicdrive.com/) for full source code 

* Last updated Nov 9th, 05' by DD. This notice must stay intact for use 

******************************************/ 

//Configure below to change URL path to the snow image 

var snowsrc="URL COPITOS DE NIEVE" 

// Configure below to change number of snow to render 

var no = 10; 

// Configure whether snow should disappear after x seconds (0=never): 

var hidesnowtime = 0; 

// Configure how much snow should drop down before fading ("windowheight" or "pageheight") 

var snowdistance = "windowheight"; 

///////////Stop Config////////////////////////////////// 

var ie4up = (document.all) ? 1 : 0; 

var ns6up = (document.getElementById&&!document.all) ? 1 : 0; 

function iecompattest(){ 

return (document.compatMode && document.compatMode!="BackCompat")? document.documentElement : document.body 

} 

var dx, xp, yp; // coordinate and position variables 

var am, stx, sty; // amplitude and step variables 

var i, doc_width = 800, doc_height = 600; 

if (ns6up) { 

doc_width = self.innerWidth; 

doc_height = self.innerHeight; 

} else if (ie4up) { 

doc_width = iecompattest().clientWidth; 

doc_height = iecompattest().clientHeight; 

} 

dx = new Array(); 

xp = new Array(); 

yp = new Array(); 

am = new Array(); 

stx = new Array(); 

sty = new Array(); 

snowsrc=(snowsrc.indexOf("dynamicdrive.com")!=-1)? "snow.gif" : snowsrc 

for (i = 0; i < no; ++ i) { 

dx[i] = 0; // set coordinate variables 

xp[i] = Math.random()*(doc_width-50); // set position variables 

yp[i] = Math.random()*doc_height; 

am[i] = Math.random()*20; // set amplitude variables 

stx[i] = 0.02 + Math.random()/10; // set step variables 

sty[i] = 0.7 + Math.random(); // set step variables 

if (ie4up||ns6up) { 

if (i == 0) { 

document.write("<div id=\"dot"+ i +"\" style=\"POSITION: absolute; Z-INDEX: "+ i +"; VISIBILITY: visible; TOP: 15px; LEFT: 15px;\"><a href=\"http://dynamicdrive.com\"><img src='"+snowsrc+"' border=\"0\"><\/a><\/div>"); 

} else { 

document.write("<div id=\"dot"+ i +"\" style=\"POSITION: absolute; Z-INDEX: "+ i +"; VISIBILITY: visible; TOP: 15px; LEFT: 15px;\"><img src='"+snowsrc+"' border=\"0\"><\/div>"); 

} 

} 

} 

function snowIE_NS6() { // IE and NS6 main animation function 

doc_width = ns6up?window.innerWidth-10 : iecompattest().clientWidth-10; 

doc_height=(window.innerHeight && snowdistance=="windowheight")? window.innerHeight : (ie4up && snowdistance=="windowheight")? iecompattest().clientHeight : (ie4up && !window.opera && snowdistance=="pageheight")? iecompattest().scrollHeight : iecompattest().offsetHeight; 

for (i = 0; i < no; ++ i) { // iterate for every dot 

yp[i] += sty[i]; 

if (yp[i] > doc_height-50) { 

xp[i] = Math.random()*(doc_width-am[i]-30); 

yp[i] = 0; 

stx[i] = 0.02 + Math.random()/10; 

sty[i] = 0.7 + Math.random(); 

} 

dx[i] += stx[i]; 

document.getElementById("dot"+i).style.top=yp[i]+"px"; 

document.getElementById("dot"+i).style.left=xp[i] + am[i]*Math.sin(dx[i])+"px"; 

} 

snowtimer=setTimeout("snowIE_NS6()", 10); 

} 

function hidesnow(){ 

if (window.snowtimer) clearTimeout(snowtimer) 

for (i=0; i<no; i++) document.getElementById("dot"+i).style.visibility="hidden" 

} 

if (ie4up||ns6up){ 

snowIE_NS6(); 

if (hidesnowtime>0) 

setTimeout("hidesnow()", hidesnowtime*1000) 

} 

En la parte que está marcada con Celeste es donde ponen la url de los copos y la parte Naranja la cantidad ya sea 10,20,35,etc

Aca les dejo algunas url de estos copos de nieve, si quieren otros x comentario les paso alguno. 

rojo

Blanco

Negro

Aclaracion: Tambien en vez de efecto de nieve puede ser  cualquier imagen y q parezca una lluvia 

Ojala les haya Servido! =D