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jquery select multiple while traversing DOM

I am trying to select all elements with the "findme" class, and from those get the selects that are nearby them.
http://jsfiddle.net/R93md/1/
Specifically I have tried
$(".findme").parent().prev().first();
then once I have all selects I plan on doing a
.each(function (){doSomething(this);})
to each select. I am stuck getting the selects because it seems that I am never going down and retrieving the contents of the span.

$(".findme").closest("td").find("select").each(function() {
doSomething(this);
});

I think you should follow this:
$('.findme').each(function(){
var el = $(this).closest('td').find('select');
dosomething(el);
});

I would first grab the parent <td> element and then use find() like so
$('.findme').parents('td').find('select').each(function(){
...
});
http://jsfiddle.net/JYGK3/
Edit:
In review of the other answers here, I've concluded that you probably should use closest() rather than parents(). If the table is nested, it could produce unwanted results.
http://jsfiddle.net/JYGK3/1

You can use .closest() to go up to the common <td> and then .find() to go down from there to find the neighboring <select>:
$(".findme").each(function() {
var select = $(this).closest("td").find("select");
// now do what you want to with the neighboring select object
// here you have access to both this which is the findme object
// and select which is the select object
});

How to search all <input> descendants of a DOM element and disable them

Let's say that I have a DOM object:
var a = document.getElementById('parent')
I want to search all input inside element a.
What should I do in jQuery?
I want to disable all input inside a, like syntax below:
$('#parent input').attr('disabled',true);
I tried
$(a).children('input').attr('disabled',true);
but gave no results.
Note: var a is an element I got from another function.

$(a).find('input').prop('disabled', true);
children() just searches immediate children of the element while find() searches all descendants.
Update: Also consider sinsedrix's remark on the difference between attr() and prop().

Don't forget attr is for HTML attributes and prop for DOM properties, try this:
$(a).find('input').attr('disabled','disabled');
or
$(a).find('input').prop('disabled',true);

$(a).find('input').attr('disabled',true)

$(a).find('input').attr('disabled',true);

jquery: Finding the last child from a selector

For example, I've got a selector here
var $myNeeds = $('.history');
This selector would have multiple divs inside, and now I want to get the last child from it, how to do this?
I tried $myNeeds.last(), this won't work!

Alternatively....
$myNeeds.find('>:last-child')
jsFiddle.

You're almost there...
$myNeeds.children().last()
The last method gets the last element in your set.
You want the last child of your set, so you need to get a new set with the children.
You could also write
$('.history > :last-child')
or
$myNeeds.children(":last")

Get value of last option of a drop down?

I have dropdown menu..which is dynamic.. How can get value of the last item in that drop down (using jquery is also acceptable)

With jQuery it's super easy:
var lastValue = $('#idOfSelect option:last-child').val();
With plain Javascript it's not much worse:
var theSelect = document.getElementById('idOfSelect');
var lastValue = theSelect.options[theSelect.options.length - 1].value;

With jQuery:
$('select option:last').val()
Of course you should use a proper ID to address the select element.
If you mean "menu" it terms of a list, you can do it similar:
// gives the text inside the last <li> element
$('#menu li:last').text()
// gives you the attribute 'some_attribute' of the last <li> element
$('#menu li:last').attr('some_attribute')
The key here is to use the :last selector.

One more way of doing this
$('select option').last().val()
or for list
$('ul li').last().text()
While above 2 suggestions are perfectly valid, I feel this approach is cleaner than modifying the selector.
Offcourse you should add id/class of specific select/ul if you want to target the particular menu/list.

Using attributte selected.
$('#SelectName option:last-child').attr('selected', 'selected');

$('#id_of_select option:last-of-type').click();
OR
$('#id_of_select option:last-child').click();
Both of these should find and click on the last option on any dynamic drop-down list.

How to gain access to an element on the same level in the DOM?

<div id="dad">
<img id="mum">
<input>
</div>
With jQuery, how could i get access to the input element, get is value or set it for example? I can't work out how to access something on the same level.. and i dont want to be using ID's, just parent/child nodes so i can use the code for loads of dad div's
Thanks!

an addition to Zed,
$(this).parent().children('input');
if you give a name to your input field then you can easily select throughout the others,
$(this).parent().children('input[name=my_input]');
then you can give any value as:
$(this).parent().children('input[name=my_input]').val('any value');
Sinan.

var myEl = $("#dad").children(":input");

$(this).parent().children() ?

Try this, to find the first child input element:
jQuery("div").find("input:first")

If i understand question, you would like achieve input from mum leve?
So try $("#mum ~ input")...
BTW, great site to search jquery function by category http://visualjquery.com/ +nice example.

I guess you want to find siblings (node with same depth and same parent and in DOM tree)
$(el).next() - next element (sibling) for all elements in the set
$(el).nextAll - all following siblings
$(el).nextUntil - all following siblings, stop on some condition (not including first "bad match").
Besides, you have next adjacent selector (+) and next sibling selector.
The same about prev, prevAll and prevUntil.
And you even have a siblings method.
Check this out.