I guess you could take your method and expand upon it slightly to deal with this stuff...

kind of pseudocode  :

List<string> parsedTokens = new List<String>();
string[] tokens = myString.split(' ');
for(int i = 0; i < tokens.Length; i++)
{
    // need to deal with the special case of the last item, 
    // or if the following item does not contain a colon
    if(i == tokens.Length - 1 || tokens[i+1].IndexOf(':' > -1)
    {
        parsedTokens.Add(tokens[i]);
    }
    else
    {
        // this bit needs to be refined to deal with values with multiple spaces...
        parsedTokens.Add(tokens[i] + " " + tokens[i+1]);
    }
}

Edit

Another approach would be to split on the colon... That way, your first array item would be the name of the first key, second item would be the value of the first key and then name of the second key (can use LastIndexOf to split it out), and so on. This would obviously get very messy if the values can include colons, or the keys can contain spaces, but in that case you'd be pretty much out of luck...

I guess you could take your method and expand upon it slightly to deal with this stuff...

Kind of pseudocode:

List<string> parsedTokens = new List<String>();
string[] tokens = myString.split(' ');
for(int i = 0; i < tokens.Length; i++)
{
    // We need to deal with the special case of the last item, 
    // or if the following item does not contain a colon.
    if(i == tokens.Length - 1 || tokens[i+1].IndexOf(':' > -1)
    {
        parsedTokens.Add(tokens[i]);
    }
    else
    {
        // This bit needs to be refined to deal with values with multiple spaces...
        parsedTokens.Add(tokens[i] + " " + tokens[i+1]);
    }
}

Another approach would be to split on the colon... That way, your first array item would be the name of the first key, second item would be the value of the first key and then name of the second key (can use LastIndexOf to split it out), and so on. This would obviously get very messy if the values can include colons, or the keys can contain spaces, but in that case you'd be pretty much out of luck...