In Swedish, isn't there a way for us to type the modified vowels as there is in other languages?
On Windows if you go to "Control Panel > Clock, Language, Region > Language" You can set up an alternate keyboard layout that you can switch to when practicing a language.
For instance, my normal keyboard layout is regular "US" and then I have a "Swedish" layout that I switch to when writing in Swedish. It's pretty simple to set up.
To set it up just click on 'options' for your current layout then under input method click 'Add an input method'. Then you can just find the language you want to add support for in the list, select it, and click 'add'. Now you should have new button on your task bar that you can click to switch between the two keyboard layouts(shortcut: windows + space).
On 10.8 or later you can just hold the key until a window pop up then press a number to select the letter. Just like on iOS, except the number part. :) I personally added the swedish layout in the keyboard settings. This way I can change the layout with a keyboard shortcut.
I use the US-International layout in Windows. Then you have: " then a gives ä, " then o gives ö, and Right Alt + w gives å. The advantage is you don't need to learn a new layout, just to get used to some quirks, like hitting spacebar, if you don't need to modify the vowel after "
There may be more efficient ways, but I have been using Alt + Unicode numbers. So, basically, hold Alt and type in some numbers from the keypad as follows:
ä = 0228 å = 0229 ö = 0246
These numbers will be different for the upper case (don't know them to hand), but they are easy to find with Google, Character Map or even menus for selecting exotic symbols in programs like Word.
In Mac OS X you can just hold down the button and all the modified letters will pop up. Same with iOS. If you are using Android I recommend TouchPal keyboard: ?ö, ä and å have their own buttons (next to p and l) which mimics physical swedish keyboards; on a single button press you can easily switch between languages which is good for language translation exercises where the languages alter all the time. It also has a very good curve writing mode which I recommend not using when typing swedish phrases so that you can learn the correct spelling. On top of all it's free :)