Here an inkscape answer (summarizing the comments and some additional info). There are two ways to include LaTeX input
1) Use the pdf+LaTeX export built into Inkscape
Built-in, text stays editable
Tex code can be typed but is not rendered, hence you may need to adjust the x,y positioning values later in your document --> annoying.
Further, no line break is supported and you need to add a parbox or minipage or something later manually
2) Get the textext plug-in for inkscape
Render the code directly in you inkscape document, including line breaks etc.
Text becomes a svg picture and can not be edited outside of Inkscape (no problem within Inkscape of course). This means after exporting and including the pdf in your document scaling your graphic will cause the text to scale too --> Possibly undesired effects
Installation details for textext:
Get the Inkscape plugin
textext from here
Installing it was a bit tricky for me (Inkscape 0.48).
First I placed the extension files in the ~/.config/inkscape/extensions folder
Then I installed Pstoedit fia the Ubuntu package manager
After that I was presented with an Error from some python modules. This blog post solved it for me:
After that I was able to select Extensions->Textext from my Inkscape menu bar. In the box that pops up type you LaTeX code just like you would in a normal document. You can specify a preamble file. I'd include any packages affecting the font in your document as the result is a SVG image of you TeX input, meaning that the font will not change if you decide to change your LaTeX-preamble at some point